Procedural organs, sealed doors and genes, special rooms and room traits, traits across seven tiers, shot synergies, elemental power-ups, CRISPR and extra lives. No two runs play the same.
First steps
Every Infect Game Mode run begins by infecting a host. As your lineage grows, you can start deeper, and new systems arrive one at a time.
Each run opens on a random host under a big INFECTED title, and the run begins right underneath it. Usually it's a person, but sometimes you land in one of the setting's animals.
Once your lineage has reached deeper organs, a map of area cards lets you start in any organ you've already reached. Each card shows the organ and its boss.
Starting past the first organ opens a draft of traits to make up for the organs you skipped. You always get the same number of picks, however deep you start.
A brand-new save shows only the DASH button. Your signature ability appears after your first finished run and your ultimate after your second, so you learn them one by one.
The first time you meet an enemy, boss, room type, hazard or system, a short notice slides in at the bottom of the screen without pausing the action.
New saves fight in compact single-screen rooms with a single wave. As your lineage grows, bigger rooms, narrow corridors and longer multi-wave fights gradually open up.
Procedural organs
Each organ is a branching map of rooms, generated fresh every run. Beat the boss at the far end to descend, from the Nasal Passage to the Brain.
Maps grow like a tree from the start room, with clear dead ends and no loops. The boss waits at the deepest dead end, and every organ holds a Mutation Chamber and a Gene Chamber.
Where you arrive in each organ: a calm, already-cleared single-screen room. Arriving shows the organ's name and your goal, and this room never rolls a tier.
Most rooms are fights, in many sizes and shapes: rectangles, L-shapes, crosses, U-shapes, rings and narrow corridors. Tissue walls and nodules give cover, and clear lanes always link every door to the centre.
The first wave lingers around the room unaware of you, while later waves pour in as reinforcements already hunting you. Later organs, rooms farther from the start and bigger rooms all bring more waves.
Doors seal while anything hunts you and stay shut until the room is clear, though tumor rooms never lock. Once you've seen a room, its door glows in that room's colour.
Clearing a fight room heals you a little and can leave a mutation orb or a vesicle chest behind. As your lineage grows, a rival virus or a run modifier may turn up too.
Beat the organ's boss for loot and a passage down; you confirm first, since there's no coming back, and descending heals you. Defeat the Microglia in the Brain to fully infect the host.
Each organ is a clean slate: leftover pickups stay behind, and running power-ups and CRISPR wear off. Killer T cells lose your trail, but a tumor left alive follows you down as a metastasis.
In Infect Game Mode, every organ you push past your starting organ in a single run makes cells tougher. Starting deeper resets this, so a fresh deep start meets the organ at its base strength.
Pickups you didn't collect stay exactly where you left them, from nucleotides and gear to untaken mutation orbs. Walk out of a fight mid-wave and it resumes from the wave you reached.
The first organ, where you hunt down the Mast Cell. Mucus puddles slow you, sneezing nerve endings and cilia carpets push you around, and the Mucolytic Enzyme gene opens its mucus plugs.
Reach the Alveolar Macrophage past coughing nerve endings, cilia carpets and gusting air sacs. The Fusion Peptide gene found here lets you slip through tight junctions.
Ride the current to the Plasma Cell while drifting red blood cells shove you around. There are no nerve endings in the blood, and the Plasminogen Activator gene dissolves fibrin clots.
Break the Follicular Helper T Cell's command. Reticular fibres strung across rooms snag you and cells alike, and the Plasminogen Activator gene opens the way again.
Get past the Paneth Cell's defensins. Peristalsis waves sweep through rooms, carrying everything with them, and the Mucolytic Enzyme gene returns to clear the mucus plugs.
Survive the Kupffer Cell's filter while bile ducts spray across the room. The Fusion Peptide gene opens the way, and from here on, mutation orb offers are never Common.
Take over the Hematopoietic Stem Cell. Stem cell niches let you heal at the cost of fresh neutrophils, and the Mucolytic Enzyme gene opens the sealed door.
Cross the blood-brain barrier, where every cell takes less damage, and defeat the Microglia to win the run. Synapses arc electricity between neurons, and the Fusion Peptide gene opens the way.
Metroidvania gates
Every organ seals one door until you carry its gene. That gene waits in a Gene Chamber, guarded by a key guardian, reachable without passing that door.
A door the host has sealed shut with a mucus plug, a tight junction or a fibrin clot. Usually it blocks the way to the boss; otherwise it guards the Mutation Chamber.
Dissolves mucus plugs, and mucus no longer slows you down. You'll find it in the Nasal Passage, the Gut and the Bone Marrow.
Lets you slip through tight junctions, and your dash damages any cell you pass through. You'll find it in the Lungs, the Liver and the Brain.
Dissolves fibrin clots, and platelet clots no longer slow you down. You'll find it in the Bloodstream and the Lymph Node.
Beyond the fights
Special rooms play by their own rules and are outlined in colour on the minimap. Some appear in every organ; others unlock as you level up.
An upgrade room at a dead end where a loose strand of DNA drifts. Inside you'll find a free mutation orb, a vesicle chest and a few nucleotides.
A key guardian holds this organ's gene. Beat it, take the gene from where the guardian stood, and the sealed door is yours to open.
Bind every receptor at once: pads sit on a ring around the room, and you must light them all before the first one fades.
Repeat the signal: watch the pads flash in order, then step on them in the same order. It's a memory test in the middle of a hostile organ.
Solving either puzzle releases a strand of DNA and a pile of loot: a mutation orb, a vesicle chest, nucleotides and Chaperone Proteins.
A crossroads of altars, each a bargain offering something strong for a price. Step onto one to take it, or simply walk away.
The doors seal and immune reinforcements keep pouring in. Survive until the timer runs out and the room's cells retreat, leaving a vesicle chest and a mutation orb.
Bathe in the pool for a random trait, often a rare one, paid for with some of your current health. The price can never kill you.
The doors seal around a group of host cells, and you race the clock to burst as many as you can. Every one drops nucleotides.
A quiet host cell: slip inside to heal and shake off the immune system. Detection drops and hunting cells lose track of you.
Each organ holds two or three different event rooms, picked from Immune Siege, Mutagenic Pool, Lysis Chamber and Refuge, so the mix changes from organ to organ.
A cancer grows here, a different one in every organ. Destroy it for a huge payout before it spreads, or back out and let it keep growing.
Gifts with prices
Each Trade-off Altars room shows a few of these bargains. Take one and the rest vanish, and your max HP can never drop below a safe minimum.
Trade toughness for power. You give up a slice of your maximum health in exchange for a big boost to the damage you deal.
Two random traits at once, paid for with a chunk of your maximum health. A gamble that can kick-start a build in a single step.
A full heal that gets you noticed. Your health is restored completely, but the immune system's Detection jumps up in return.
Faster but more fragile: your virus moves noticeably quicker, paid for with some of its maximum health. Good if you'd rather outrun hits than absorb them.
Grab a big pile of nucleotides with an even mix of every base, but the scavenging raises the alarm and pushes your Detection up.
Late unlock
Once Room Tiers unlock, every room except the start rolls a tier from Common to Prismatic. Higher tiers carry more boons and more drawbacks.
A plain room with no traits at all. Common rooms are the norm early on and grow less frequent as you push deeper toward the Brain.
A small gift: one boon and no drawbacks. Uncommon rooms turn up at a steady rate in every organ, so they're a safe little bonus.
A fair trade: one boon balanced by one drawback. Rare rooms grow more common the deeper you go, so expect more of them near the Brain.
The scales tip your way: two boons against a single drawback. Epic rooms are uncommon early on but appear more often in deeper organs.
High stakes: two boons and two drawbacks share the room. Legendary rooms are scarce in the Nasal Passage and grow more frequent toward the Brain.
A rare sight: three boons and two drawbacks, leaning in your favour while still biting back. Mythic rooms show up a little more often deep in the host.
The rarest room of all: three boons and three drawbacks, outlined on the minimap in cycling rainbow colours. Finding one is a real event.
Boons and drawbacks
The boons and drawbacks a tiered room can carry. They only apply while you're inside, and opposite traits never share a room.
A generous room that yields far more nucleotides than usual, perfect for stocking up. It's the opposite of Barren, so the two never share a room.
The cells here are frailer than normal and go down noticeably faster. It's the opposite of Fortified, so you'll never meet both in the same room.
Cells in this room move slower than usual, giving you more space to dodge and reposition. It's the opposite of Frenzied, so they never appear together.
The tissue here is especially receptive, so every hit you land deals more damage than usual. A simple, welcome boost for clearing the room faster.
Detection rises much more slowly in this room, so you can fight longer before the immune system catches on. It's the opposite of Alarmed.
Clearing this room always leaves a mutation orb behind, so fighting through it guarantees you a fresh trait to choose for your build.
Clearing this room leaves a vesicle chest behind, a membrane bubble you can burst open for loot such as gear, nucleotides and materials.
Clearing this room heals a good chunk of your maximum health, with a RESTORED notice to let you know. A welcome breather on a long run.
Power-ups drop far more often in this room, including elemental power-ups and the rare CRISPR, so expect a burst of extra firepower.
A meagre room that yields far fewer nucleotides than usual. It's the opposite of Nutrient-Rich, so the two never share a room.
The cells here are tougher than normal and take noticeably longer to bring down. It's the opposite of Weakened Defenses, so the two never share a room.
Cells in this room move faster than usual, closing in quickly and leaving you less room to breathe. It's the opposite of Sluggish Cells.
Cells in this room hit noticeably harder than usual, so every mistake costs more health. Lean on your dash and keep your distance.
Detection climbs much faster in this room, so the immune system notices you sooner. It's the opposite of Quiet Tissue, so the two never share a room.
Elite cells are far more common in this room, so expect tougher enemies with dangerous affixes. Their better loot can make the fight worth it.
The room slowly eats at you, draining health for as long as cells are hunting you. Luckily, it can never finish you off on its own.
Tissue fights back
Each organ has its own family of living hazards, and they hurt cells as readily as they hurt you, so lure the immune system into them.
Bottomless gaps in the tissue. Dash over them safely, but stop on one and you fall in, losing a chunk of health before climbing out at the edge.
A glowing shaft hidden in some organs. Walk in and the current sweeps you into a freshly reshuffled layout of the same organ.
Sticky puddles that slow you right down while you stand in them. They appear in every Nasal Passage room, starting from your very first run.
Glowing nerve fibres in the walls. Linger on one, or shoot it, and it fires a reflex blast that flings everything nearby: a sneeze in the nose, a cough in the Lungs.
Carpets of beating hairs that carry anything standing on them in the direction the arrows point, you and immune cells alike.
Alveoli on the walls swell up, then exhale a gust that blows you and nearby cells away, clearing enemy shots out of the air as well.
Solid cells drifting along with the flow. They shove you around and soak up shots from both sides, acting as moving cover.
Fibres strung across the room that drag you down to a crawl and snag cells too. Shoot them to snap them and clear your path.
Every so often the gut wall clenches and a wave sweeps across the room, carrying everything along with it, you and the cells alike.
Ducts in the walls spray a jet of bile across the room after a flashing warning line. It burns cells far worse than it burns you.
A pod of young blood cells. Burst it by touch or with a shot to heal, but fresh neutrophils pour out to join the fight.
Pairs of neurons that fire an electric arc between them every few seconds, after a flickering warning. The arc hurts cells too, so use it.
Mutation orbs
Mutation orbs offer a choice of traits that last the whole run. Pick the same trait again and it stacks, and new families unlock as you level up.
The simplest upgrade there is: it raises all of your damage. Every extra pick compounds on top of the last, so stacking it pays off quickly.
Your virus fires faster, putting more shots into every fight. Like other stat traits, each extra pick compounds with the ones you already hold.
Raises your move speed so you can weave through crowds and dodge more easily. Each extra pick compounds with the ones you already hold.
Raises your maximum health and heals you by the same amount on the spot, making it both a safety net and an instant top-up.
Adds extra projectiles to every shot, with even more at the highest tiers. It's offered rarely, and grows rarer still each time you take it.
Your shots pierce through extra cells, more at higher tiers. It's also one of the shot-changing traits that pair up into synergies.
Your signature ability charges faster and refills right away. Each extra pick compounds, so you can lean hard on your class power.
Your shots set cells burning, dealing damage over time after each hit. Higher tiers make the flames hotter, turning every shot into a lingering threat.
Your shots poison cells, and the poison stacks up with repeated hits. Higher tiers make each stack hurt more, rewarding steady fire on one target.
Your shots sometimes chill a cell and slow it down for a moment. Higher tiers deepen the slow, though a cell only carries one chill at a time.
Your shots turn electric: they tear through shields, can shock, and arc to a nearby cell. Armor isn't affected, so it shines against shielded enemies.
Shots burst on impact, hurting every cell around the hit. The blast grows with each pick, and it's one of the shot-changing traits behind synergies.
Your shots jump on to more cells after the first hit, chaining through a crowd. Higher tiers add more jumps, and it's a shot-changing trait for synergies.
Shots bounce off walls and tissue instead of stopping, so missed shots get a second chance. Higher tiers add more bounces, and it forms synergies too.
Shots fly out to full range and come back, hitting again on the return. Extra picks add more round trips; it's rarely offered and forms synergies.
Satellite virions orbit around you and damage any cell they touch. Higher tiers add more satellites and make each one hit harder, building a spinning ring of damage.
You release a pulse of damage around yourself on a regular timer. Higher tiers pulse more often and hit much harder, punishing cells that crowd in close.
Small homing darts bud off both your sides on a timer. More strength fires them more often and adds extra pairs, though darts don't carry your other shot traits.
A shield that soaks up incoming hits and recharges after a short break from damage. It shows as a cyan line under your health bar.
Armor that absorbs part of every hit and regrows once you avoid damage for a while. It shows as a grey line under your health bar.
Grants an extra life: the next time you'd die, you go dormant and respawn with part of your health. It's very rarely offered and needs Extra Lives unlocked.
Every dash bursts where you leave, then leaves behind a ring that keeps hitting cells. More dash-burst traits make the ring bigger and longer-lasting.
Your dash bursts leave a ring that sets cells burning. It shares a single ring with your other dash-burst traits, so their effects combine in one spot.
Your dash bursts poison cells and leave a toxic ring behind, which keeps adding more poison to anything that lingers inside it.
Your dash bursts leave a chilling ring that can slow cells for a moment. Higher tiers make the slow stronger, helping you escape or kite a crowd.
Your dash bursts leave a charged ring that jolts cells with electric damage. Higher tiers make every jolt hit much harder.
Makes your dash bursts and their rings bigger, spreading every dash effect over more ground. It's only offered once you already hold a dash-burst trait.
Your dash becomes a teleport through cells and tissue walls, reaching farther at higher tiers. It always lands at the farthest safe spot, never in a wall or pit.
A little helper virion follows you around and keeps shooting the nearest cell. Each extra pick adds another helper, building a small escort of your own.
Every power-up lasts longer, CRISPR included, giving you more time to rampage while it's active. Higher tiers stretch the duration even further.
Every power-up appears more often, CRISPR included, so you spend more of each fight powered up. Higher tiers raise the drop rate much further.
Every power-up starts and ends with a big blast around you. The blast grows with each pick, turning every pickup into a double explosion.
Every kill while a power-up is running keeps it going longer. With CRISPR, every cell you cut extends it, so a good streak can last a long time.
Makes every elemental power-up stronger, from Chain Lightning to Umbra. Higher tiers push the boost much further for players who love chasing power-ups.
Deal more damage to tumors and their cells, helping you destroy a cancer before it spreads. It unlocks alongside Tumors & Metastasis.
Common to Prismatic
Every offered trait rolls a tier that multiplies its strength. Deeper organs improve the odds, and your virus's milestones cap how high a tier can go.
The baseline tier, giving a trait its normal strength. It's the most frequent offer early on, but from the Liver onward, offers are never Common.
The green tier, a step up from Common with noticeably stronger traits. Uncommon offers show up regularly, even in the Nasal Passage.
The blue tier, and the highest a brand-new virus can roll. Rare traits pack a real punch and become more common as you push deeper.
The purple tier, where traits get seriously strong. It only appears once your virus reaches the Epic & better traits milestone, and deeper organs raise its odds.
The orange tier, a big jump in power that's rare even in deeper organs. It unlocks with the Legendary & mythic traits milestone, later in your lineage.
The red tier, a truly rare roll that makes any trait hit far harder. At this tier, Segmented Genome even adds an extra projectile on top.
The top tier, shown in cycling rainbow colours. It's the rarest trait roll of all, a little likelier in the Brain, and makes any trait enormously stronger.
Shot-trait pairs
Five traits change how your auto-attack behaves. Hold any two and their pair synergy switches on instantly, with no limit to how many you can hold.
Returning shots already pass through cells, so pierce turns into raw power. Every cell a shot cuts through makes the rest of its trip hit harder.
Every bounce becomes an extra round trip, so instead of fading, your shots fly back out again and keep working the room.
Your shots burst at the exact point where they turn around, right in the middle of the crowd you were aiming at.
Shots on their way back zap the nearest cell over and over, turning every return trip into a crackling sweep of extra damage.
Each bounce restores a pierce and adds damage, so shots that ricochet around a room keep drilling through cells and hitting harder.
After passing through a cell, a shot's bursts get wider and stronger, so piercing shots explode with extra force deeper in a crowd.
Chain jumps pierce just like the shot that started them, so every jump can slice through a whole line of cells.
Every bounce off a wall sets off a burst where it hits, so ricochets turn the edges of the room into a minefield.
Every bounce fires a chain jump at the nearest cell, sending your shots ricocheting around the room like a pinball machine.
Every burst arcs to one more cell outside its blast, dealing electric damage, so explosions keep spreading through the crowd.
Early unlock
Power-ups drop from the first cells you kill, never the last, so there's always a fight to use them on. Several can run at once.
The rarest power-up, and it works like a star: for a short time you're invincible and faster, and every ordinary cell you touch is cut apart.
Run over cells to shred them while nothing can hurt you. You move a little faster, and every touch damages a cell and shoves it aside.
Lightning arcs out of you and chains between cells in rapid bursts, dealing electric damage to every cell it jumps through.
Four flamethrower jets spin around you, scorching everything they sweep across and leaving cells burning even after the flames have passed.
Waves pulse out of you over and over, pushing cells back and washing away any enemy shots caught inside them.
You move much faster and blow enemy shots back at the cells that fired them, while nearby cells are pushed away.
You take far less damage while a ring of boulders orbits you, crushing cells they hit and stopping enemy shots in their tracks.
Every cell near you is slowed and chilled, and each moment there's a small chance one freezes solid. Bosses are slowed less and never freeze.
Most hits drift harmlessly through you, shown as MISS, while cells caught in the mist build up poison stacks over time.
You heal steadily over time while bursts of light flare out and burn nearby cells, making it a lifesaver in a tight fight.
A wide dark aura drains cells to heal you, drained cells burst into shadow novas, and your shots hit much harder while it lasts.
Floor loot
What cells, chests and rooms leave behind during a run. Pickups from one organ don't follow you into the next.
A glowing DNA orb: touch it to choose one of three traits for the rest of the run. Cleared fights often leave one behind.
A membrane bubble you walk into to burst open. Inside are nucleotides and Polymerase Shards, sometimes gear or a Chaperone Protein, and very rarely a Dormant Virion.
Piles of A, T, C and G that drop from every cell you kill, counted on the HUD during the run. You spend them on Petri Lab upgrades, gear combining and more.
The common material for enhancing your gear. Kills drop them fairly often, and every vesicle chest holds a handful, so they pile up quickly.
A material for enhancing gear from its first enhancement upward. Bosses drop several, Killer T cells and solved puzzles give a few, and many vesicle chests hold one.
The rare material for pushing gear to its highest enhancements, dropping only in Endless Game Mode. In Infect Game Mode and Pandemic Game Mode, it condenses into Chaperone Proteins instead.
A rare purple strand used for advanced Petri Lab upgrades and skill tree respecs. It only drops in Pandemic Game Mode and breaks down into nucleotides elsewhere.
Equipable gear drops mid-run with a NEW GEAR notice showing its level and tier. Elites drop it far more often, and in better tiers, than ordinary cells.
A rare amber cyst labelled EXTRA LIFE, storing an incubation for this run. Bosses, rival viruses, tumors, treatments and tough elites can all drop one.
Once Run Modifiers unlock, a finished modifier can drop and go straight into your stock, with a MODIFIER FOUND notice to celebrate.
Second chances
A run ends when your health hits zero, unless you're holding a stored incubation. Extra lives arrive once the Extra Lives mechanic unlocks.
When you'd die, a stored incubation is spent instead: you collapse into a dormant cyst and re-emerge a moment later at the safest spot in the room.
Extra lives come from Dormant Virion drops and the Incubation Period trait, and last only for the current run. You can only hold a few at a time.
Being knocked out during an Immune Siege or Lysis Chamber fails the room, not the run, so these challenges are always worth a try.
Health comes back in set amounts as you make progress: clearing fights, beating bosses and descending to the next organ all patch you up.
The SKILL button
Equip one active skill from the skill tree and it gets its own SKILL button and cooldown. Each skill grows stronger and recharges faster as it ranks up.
Blast every cell near you and knock them all back, clearing space when a crowd closes in. Higher ranks hit harder and come back sooner.
Turn to mist for a moment, becoming untouchable and much faster. It's a clean escape button, and higher ranks keep you misty for longer.
Heal a chunk of your health and take reduced damage for a short time, perfect for turning a losing fight around. Higher ranks heal more and recharge faster.
Move, dodge, fire
You steer and dodge while your virus aims and fires on its own. Play with touch, keyboard, mouse or a game controller.
On touch screens, a floating joystick appears wherever you touch the left side of the screen. Keyboard, mouse and game controllers all work too.
Your virus fires on its own at the nearest cell it can see, so you can focus on moving. It never fires through tissue.
Hit a cell before it notices you and you deal heavy bonus damage, with an AMBUSH callout. The hit alerts that cell, and it starts hunting you.
A quick burst of movement you can't be hurt during, with a moment of protection after. It recharges fast and carries you safely over abyss pits.
Your class's signature ability charges as you kill. Tap it when the ring is full and glowing, but beware: using it raises Detection.
Your ultimate charges as you hit and kill cells and glows when it's ready. Each virus has its own, from Pandemic to Superspreader Event.
Keys are laid out like a controller's face buttons, so switching between keyboard and gamepad feels natural. Controller buttons can be remapped in Settings.
The pause button in the top right freezes the run and gives you a full picture of your build and the room you're in.
Reading the screen
Everything you need mid-fight sits around the play window: health top left, the immune system's mood top right, buttons bottom right.
A heart and a health bar that shift from green to yellow to red as you take damage, with a draining trail so every hit reads clearly. At low health the screen edges pulse red.
An hourglass at the end of your health bar shows how many stored incubations you have, so you always know how many second chances remain.
A pill beside your health shows your virus's live state, such as Influenza A's current shot type, Retrovirus's stored cells, Filovirus's bleeding cells or Halovirus's current variant form.
The organ's name and how many of its fights you've cleared so far, so you can see your progress at a glance. Endless Game Mode shows the set number instead.
An eye meter tracks how aware the immune system is of you, shifting from calm green to wary yellow to a pulsing hunted red. Fill it and Killer T cells come for you.
A level shown beside the eye reveals how much the immune system has learned. It climbs with every organ you reach and every Killer T generation you destroy.
A thin bar with a hurricane icon under Detection shows how far ahead your build is. Push it past its mark and the immune system sends crimson adapted cells.
A flame shows the Immune Alert level, which rises over time and makes new cells tougher, while a hexagon counts the nucleotides you've gathered this run.
Shows the rooms you've visited and the ones beside them, colour-coded by status, with special rooms outlined, a skull for the boss and sealed doors in their gene's colour.
A line under the minimap lists the genes you're carrying, such as MUCOLYTIC, FUSION and PLASMIN, so you always know which sealed doors you can open.
When you face a boss, its name and health bar stretch across the top of the play window so you can track the fight at a glance.
Shows the current wave out of the total, how many cells are left and a pip for each wave. Its outline turns red on the final wave.
During an Immune Siege or Lysis Chamber, a countdown pill shows the time left and what's happening. It turns red and pulses as time runs out.
Each running power-up lists its name and remaining time on its own line, while CRISPR gets a special countdown in shifting rainbow colours.
A red line warns you when the immune system has started resisting one of your shot types, a hint that it might be time to mix things up.
Counts down to the tumor's next growth or spread and shows its current stage and how far it has spread, so you know how long you can wait.
DASH, your signature ability, ULT and SKILL sit in a staggered cluster, each ringed by its charge or cooldown. The signature and ultimate buttons glow when ready.
Grows with you
New players aren't buried in systems on their first run. Each mechanic unlocks for your whole save as you level, then arrives in your next run.
Elemental power-ups and CRISPR start dropping from the first cells you kill in a fight. This milestone also opens the power-up traits for your mutation orbs.
Trade-off altars, receptor puzzles and event rooms such as the Immune Siege, Mutagenic Pool, Lysis Chamber and Refuge start appearing across the organs.
Cells can now come in stronger tiers with affixes like Shielded, Swift or Vampiric. They're tougher to take down, but they drop better loot.
Dormant Virions can now drop from tough enemies, each one an extra life. The organ that introduces them hands you one after a cleared fight.
Filling Detection all the way sends elite hunters after you, and they follow you from room to room, so staying hidden matters more than ever.
Most organs now grow a tumor that spreads over time and follows you down if left alive. This also opens the Oncolytic Payload trait.
Each organ's living hazards appear, along with abyss pits and drop shafts. The organ that introduces them has hazards in every fight room.
Other viruses competing for the same host can now show up after a fight, adding a fresh threat and a chance at a Dormant Virion.
When Detection runs high, the host may fight back with antivirals, a vaccine booster or interferon, so keeping a low profile pays off.
Rooms start rolling tiers with boons and drawbacks, outlined on the minimap. The organ that introduces them upgrades many of its plain rooms to Uncommon or Rare.
A build that gets too strong fills the storm meter and draws adapted cells, so the immune system keeps pace with your growing power.
Lean too hard on one shot type and cells start resisting it. An L level appears by the Detection eye to show how much the immune system has learned.
Each host now carries hidden traits, revealed when you infect it, so every new body you take over plays a little differently.
Burning, poison, chill and shock traits can be offered, from Pyrogenic Fever and Cold Adaptation to dash-burst versions like Febrile Wake and Ion Surge.
Skip ahead to any area you've already reached, with a head start draft of traits to make up for the organs you skip.
Bursting, chaining, bouncing, returning and orbiting shots join the trait pool, including Lytic Burst, Fomite Ricochet, Satellite Virus and Lateral Budding.
Trait offers can now roll the purple Epic tier, a big step up in strength from anything a brand-new virus can find.
Stolen Membrane shields, Glycan Armor and the Incubation Period extra life join the trait pool, giving your build real staying power.
Trait offers can roll orange, red and even Prismatic tiers, the strongest in the game, once your virus is high level with a long lineage behind it.
Next up
XP, a three-branch skill tree, the Petri Lab, modifiers and hundreds of challenges.
