The Viruses

Shared base stats

All viruses

Every virus has Influenza A's health, damage and fire rate. The viruses are balanced through their skills instead.

• 70 max HP, 10 damage, one shot every 0.4 s
• Move speed 190 (Retrovirus 188, Halovirus 205)

Auto-attack

All viruses

Every virus fires on its own at the nearest cell it can see, and leads moving targets.

• Targets hunting cells within 380, or unaware cells within 210 (a sneak attack), never through tissue
• Hitting an unaware cell is an AMBUSH for 2.5x damage
• Influenza A's shots take their shot type's colour; the other viruses fire bolts in their own ultimate colour
• Only Influenza A changes shot type; the other three always fire standard shots

Signature ability button

Opens after run 1

Each virus has its own signature button (SHIFT, LATENT, BLEED or VARIANT), which charges as you kill.

• Opens on a new save after the first finished run
• Each kill adds 10% charge; killing the Mast Cell boss adds 40%
• Can't be used again while its effect is still running
• Antigenic Shift and Hemorrhage raise Detection by 8. Latency lowers it by 30. Variant Surge doesn't raise it

Ultimate button

Opens after run 2

Each virus has its own ultimate, which charges as you hit and kill cells.

• Opens on a new save after the second finished run
• Charges per hit (one big hit counts as at most three) and per kill
• After use it can't charge for 3 s; the button counts down
• Base radius 300 for every virus
• Using it raises Detection by 5

One lineage, four viruses

Progression

Your level, skill tree, Petri Lab and gear belong to the whole lineage. The mutation a generation is born with decides which virus it is.

• You always play your current generation's virus, in every game mode
• Only Infect Game Mode makes new generations, gives XP and offers virus jumps
• Petri Lab core upgrades and the ultimate reach and charge upgrades keep their levels across viruses; each virus also has its own branch
• Each virus has 2 challenges: Victory (win 1 run as it) and Dynasty (win 5)

Medicine by virus

Treatments

When the host gets treated, the drug it takes depends on the virus you are.

• Influenza A: the host takes Tamiflu (Antiviral Dose); the vaccine event is a Booster Shot
• Retrovirus: tenofovir (Antiretroviral Dose), and PrEP in place of the Booster Shot
• Filovirus: an antibody infusion. Halovirus: Paxlovid
• Inside a drug capsule's cloud, Influenza A fires at half speed; the other viruses' fire interval grows 1.6x

Antigenic Drift

Passive

Every 4 seconds your shot type mutates into one of the other three types at random.

• Cycles between Standard, Piercing, Splitting and Explosive, never repeating the current type
• The HUD shows DRIFT and the current type, in that type's colour
• The Rapid Drift Lab upgrade makes shots mutate 0.4 s sooner per level
• Switching types helps against memory B cells, which take half damage from the last shot type that hit them, and against the immune system learning to resist one shot type

Standard Shot

Shot type

A plain green shot.

• Colour: green
• The type every run starts with

Piercing Shot

Shot type

A blue shot that passes through cells.

• Passes through 2 extra cells
• Neuraminidase Cleave (Lab) adds +1 pierce per level
• Colour: blue

Splitting Shot

Shot type

A yellow shot that splits in two when it hits.

• On a hit, two half-damage shards fly off at an angle on either side
• Shards don't split again
• Colour: yellow

Explosive Shot

Shot type

A bigger red shot that bursts on impact and cracks armor.

• Bursts in a 70 radius for 50% of the shot's damage to other cells
• Explosive damage breaks armor 1.6x faster (good against Adenovirus and armored elites)
• Colour: red

Antigenic Shift

Signature · SHIFT

Fires a ring of every mutation at once, then 8 seconds of rapid fire with random shot types.

• Fires 16 bolts in a full circle, cycling through all four shot types, each at 150% damage
• For 8 s your fire rate doubles and every shot is a random type (HUD: SHIFT · MIXED)
• It's loud: Detection +8
• Reassortment Burst (Lab) adds +4 bolts per level

Pandemic

Ultimate

A viral wave that damages and infects every cell nearby.

• Hits every cell within 300 for 40 damage
• Infects survivors: they burn for 6 damage per second for 5 s
• Lingering Fever (Lab): infection lasts +2 s and burns +3/s per level
• The Superspreader Lab upgrade makes infected cells pass the infection to cells within 130 when they die

Influenza A Lab branch

Petri Lab

Influenza A's own Petri Lab upgrades for its signature ability and ultimate.

• Rapid Drift (4 levels): shots mutate 0.4 s sooner per level
• Reassortment Burst (3 levels): Antigenic Shift fires +4 bolts per level
• Neuraminidase Cleave (2 levels, 1 RNA to unlock): piercing shots pass through +1 more cell per level
• Pandemic Reach (3 levels): wave radius +20% per level

Viral Reservoir

Passive

Cells killed by your auto-attack shots are stored in a reservoir, ready to be released by Integration Surge.

• Holds 6 cells (Integrase Efficiency adds +1 per level); the HUD shows STORED x/6 and RESERVOIR FULL
• Only kills by your own auto-attack shots count
• Antibodies, summoned cells, bosses, mini-bosses, Killer T cells, drug capsules and vaccines are never stored

Charged Start

Passive

Every run starts with Integration Surge charged and a full reservoir.

• The starting reservoir is filled with random immune cells (neutrophils, monocytes, B cells, NK cells, macrophages, basophils, eosinophils), always including at least one macrophage
• Every other "start with your ultimate charged" effect banks one more charged Surge, with its own fresh full reservoir, ready right after you use the first (HUD: ULT +n)

Immune Hunter

Passive

Built to infect immune cells, Retrovirus tears into the big ones.

• All damage to bosses and Killer T cells is +50%

Integration Surge

Ultimate

Releases every cell in your reservoir as an ally beside you, and hits everything nearby.

• Every hostile cell within 300 takes 6x your damage (plus the +50% against bosses)
• Each stored cell comes back as an ally with 60% health that fights for 18 s
• At most 15 allies at once; a stored cell past the cap never forms
• With an empty reservoir it still hits: "The immune system turns on itself"
• Cytopathic Burst (Lab) adds +50% Surge damage per level

Captured Allies

Allies

Released cells wear your green colour and hunt down the nearest hostile cell.

• Allies strike cells they touch every 0.5 s
• Every captured cell except the macrophage is a striker that hits 1.6x harder
• Allies fight for 18 s (Viral Reservoir Lab: +5 s per level; Provirus Lab: until the room is cleared)
• Syncytia (Lab): allies explode when their time runs out (45 damage in a 95 radius)

Guardian Macrophage

Allies

A captured macrophage is your tank: it guards you and taunts cells into fighting it instead of you.

• Every 1 s it taunts up to 3 cells within 170; they chase it until it dies or its time runs out
• Never taunts bosses, mini-bosses or Killer T cells
• When a hunting cell comes within 220 of you, it dashes back at 3.5x speed to stand between you and the threat, taunting as it arrives

Kamikazes

Gut milestone

From the Gut on, every cell your shots kill adds a kamikaze to a store that releases itself when full.

• Store holds 5 (HUD: KAMIKAZE x/5, then KAMIKAZES READY)
• When the store is full and a hostile cell is present, all 5 burst out around you
• Each rushes the nearest cell and explodes on contact, or after 10 s, for 35x your damage in an 85 radius
• Their blasts grow with your captured-cell damage milestones

Latency

Signature · LATENT

Go dormant for a few seconds. Nothing can find or hurt you, and the cells around you wither.

• Lasts 4 s (Deep Latency Lab: +1 s per level)
• Detection drops by 30
• Hunting cells lose your trail, even ones that arrive mid-latency (bosses and Killer T cells keep tracking you but can't hurt you)
• You can't fire while latent
• Every 0.5 s a pulse hits every cell within 130, bosses included, for 80% of your damage

Retrovirus Lab branch

Petri Lab

Retrovirus's own Petri Lab upgrades.

• Integrase Efficiency (3 levels): store +1 more cell per level
• Deep Latency (3 levels): Latency lasts +1 s per level
• Viral Reservoir (3 levels, 1 RNA): allies fight +5 s longer per level
• Syncytia (1 level, 2 RNA): allies explode when their time runs out

Bleeding Hits

Passive

Your hits can make cells bleed.

• 45% chance per hit to start a 3 s bleed
• Bleeds for 100% of your damage per second
• A stronger bleed replaces a weaker one
• Hemorrhagic Strain (Lab): +5% bleed chance per level

Bleed-out Feeding

Passive

Filovirus feeds on cells that bleed out.

• Heals 2 HP whenever a bleeding cell dies

Hemorrhage

Signature · BLEED

Every cell nearby bleeds heavily and hits softer.

• Reaches every cell within 240 (Vascular Leak Lab: +15% per level)
• Each bleeds for 260% of your damage per second for 5 s
• Cells it bleeds deal 40% less damage (contact and shots) for 5 s, 45% less from the Gut milestone on
• Raises Detection by 8

Viral Hemorrhage

Ultimate

Every cell nearby loses about a third of its health and bleeds out, and you heal 20%.

• Ordinary cells within 300 lose 35% of their current health plus 20
• Bosses, mini-bosses and Killer T cells lose 12% of current health (at least 40)
• Survivors bleed for 200% of your damage per second for 6 s
• Heals you for 20% of your max HP

Filovirus Lab branch

Petri Lab

Filovirus's own Petri Lab upgrades.

• Hemorrhagic Strain (3 levels): +5% bleed chance per level
• Coagulopathy (3 levels): bleeding deals +15% damage per level
• Vascular Leak (3 levels, 1 RNA): Hemorrhage reaches +15% farther per level
• Hemorrhage Reach (3 levels): Viral Hemorrhage radius +20% per level

Asymptomatic

Passive

The immune system is slow to notice you: Detection rises 25% slower.

• Asymptomatic Spread (Lab): Detection rises a further 5% slower per level
• Immune Escape (Lab): a further 15% slower

Spike Volley

Passive

Every few shots, a fan of spike shots flies out on either side of your normal shot.

• Every 5th shot fires 4 extra shots in a fan, each at 70% damage
• Swarm form: every 4th shot. Swarm surge: every shot
• Furin Cleavage (Lab): volleys fire one shot sooner per level (never more often than every 2nd shot)

Infected Bursts

Passive

Infected cells pass the infection on and burst when they die.

• A dying infected cell infects every cell within 130
• It also bursts for 20% of your damage on cells practically touching it
• Halovirus's infection burns for 80% of your damage per second for 5 s

Variant Surge

Signature · VARIANT

A fitter variant takes over: you move to the next form with a big boost for a few seconds, then keep a smaller boost until the next surge.

• Fixed order: Swarm, Fury, Ghost, then Swarm again. Runs start in Swarm form, so the first surge brings Fury
• The big boost lasts 6 s (Variant of Concern Lab: +1 s per level)
• Doesn't raise Detection
• The Variant button takes your form's colour; a ring of beads shows the order with your current form on top

Swarm

Variant form

The spreading variant: spike volleys come far more often.

• Surge: a spike volley with every shot
• Form: volleys fire one shot sooner
• Colour: gold

Fury

Variant form

The virulent variant: your shots hit much harder.

• Surge: +60% damage (+65% from the Gut milestone on)
• Form: +15% damage
• Colour: red-orange

Ghost

Variant form

The immune-escape variant: faster, and cells hit you far less.

• Surge: 50% faster (even past the usual speed cap), and you take 40% less damage
• Form: 12% faster, and you take 15% less damage
• Colour: ice blue

Superspreader Event

Ultimate

A mass gathering: cells nearby are pulled into one crowd, and each one that dies bursts and spreads it on.

• Ordinary cells within 300 are pulled into a crowd, always at least 170 away from you (bosses, mini-bosses and Killer T cells stay put)
• Every cell in reach takes 5x your damage, is infected and stays exposed for 8 s
• Super-spreading Reach (Lab): +20% radius per level

Outbreak Chain

Ultimate

Each exposed cell that dies bursts into an aerosol that hits, infects and exposes its neighbours, so one kill can sweep through the whole crowd.

• Each aerosol reaches 95 and deals 18% of a cell's max health plus your damage
• Bosses, mini-bosses and Killer T cells take 2x your damage instead
• Cells it reaches are exposed for 2 more seconds, so the chain keeps going
• Long chains are called out: OUTBREAK x2, x5, x10, x15...

Halovirus Lab branch

Petri Lab

Halovirus's own Petri Lab upgrades.

• Furin Cleavage (2 levels, 1 RNA): spike volleys fire one shot sooner per level
• Variant of Concern (3 levels): Variant Surge lasts +1 s per level
• Asymptomatic Spread (3 levels): Detection rises 5% slower per level
• Super-spreading Reach (3 levels): Superspreader Event radius +20% per level

Milestones count from the deepest organ your whole lineage has reached in Infect Game Mode, whichever virus got there.

• They switch on mid-run the moment you first arrive
• Pandemic and Endless Game Mode can drop you into deep organs, but only Infect Game Mode unlocks new milestones
• Organ order: 1 Nasal Passage, 2 Lungs, 3 Bloodstream, 4 Lymph Node, 5 Gut, 6 Liver, 7 Bone Marrow, 8 Brain

Retrovirus: Lymph Node

Organ 4

Captured cells hit 25% harder and are 25% tougher.

• Ally damage x1.25, ally toughness x1.25

Retrovirus: Gut

Organ 5

Captured cells get +10% damage and +15% toughness, and every cell your shots kill adds a kamikaze.

• Unlocks the kamikaze store (5)
• Ally damage x1.1, toughness x1.15

Retrovirus: Liver

Organ 6

Captured cells get +60% damage and toughness, and Latency and Integration Surge hit 80% harder.

• Ally damage and toughness x1.6
• Latency pulses and Surge damage x1.8

Retrovirus: Brain

Organ 8

Captured cells double their damage and toughness, and Latency and Integration Surge hit 120% harder.

• Ally damage and toughness x2
• Latency and Surge x2.2 (about x4 with the Liver bonus)
• All four bonuses together: allies deal about 4.4x damage and are about 4.6x tougher

Filovirus: Lungs

Organ 2

Bleeds, Hemorrhage and Viral Hemorrhage hit 80% harder.

• Every Filovirus ability x1.8

Filovirus: Bloodstream

Organ 3

Bleeds, Hemorrhage and Viral Hemorrhage hit another 50% harder, and any bleeding cell deals 35% less damage.

• Ability damage x1.5 (x2.7 together with the Lungs bonus)
• Every cell you're bleeding is weakened, not only those hit by Hemorrhage

Filovirus: Gut

Organ 5

Bleeding gets 10% stronger, and Hemorrhage weakens cells 5% more.

• All bleeds x1.1
• Cells Hemorrhage bleeds deal 45% less damage instead of 40%

Halovirus: Lymph Node

Organ 4

Infection, spike volleys, outbreaks and the ultimate hit 80% harder.

• Every Halovirus ability x1.8

Halovirus: Gut

Organ 5

Spike volleys deal 15% more, and the Fury surge gives +65% damage.

• Volley damage x1.15
• Fury surge goes from +60% to +65%

Halovirus: Bone Marrow

Organ 7

Infection, spike volleys, outbreaks and the ultimate hit 60% harder.

• Every Halovirus ability x1.6

Halovirus: Brain

Organ 8

Infection, spike volleys, outbreaks and the ultimate hit 90% harder.

• Every Halovirus ability x1.9
• With the Lymph Node and Bone Marrow bonuses: about 5.5x in total

Unlocking by level

Level 4 / 8 / 12

New viruses open as your lineage levels up with XP from Infect Game Mode runs.

• Influenza A: from the start
• Retrovirus: level 4
• Halovirus: level 8
• Filovirus: level 12

How jumps are offered

Mutation offers

Each set of three mutation offers has a 40% chance that one of them is a jump to another unlocked virus.

• The first offer always keeps your current virus, for players who want to stay
• Half the time the parent's own mutation comes back to be inherited again (stacked); stacking a jump keeps that virus
• Abandoned runs, Pandemic Game Mode and Endless Game Mode runs don't make a new generation

Segment Reassortment

Jump mutation · Boon

Becomes Influenza A, with +10% damage.

• Stacks: +15% at 2 generations in a row, +20% at 3

Reverse Transcriptase Capture

Jump mutation · Boon

Becomes Retrovirus, with +12% max HP.

• Stacks: +18% at 2 generations in a row, +24% at 3

Filovirus Spillover

Jump mutation · Boon

Becomes Filovirus, with +15% max HP.

• Stacks: about +23% at 2 generations in a row, +30% at 3

Spike Recombination

Jump mutation · Boon

Becomes Halovirus, with +8% move speed.

• Stacks: +12% at 2 generations in a row, +16% at 3

Family Tree

Lineage

The Family Tree shows one lane per virus, with every generation your lineage has been, in unlock order.

• Lanes top to bottom: Influenza A, Retrovirus, Halovirus, Filovirus
• Locked lanes show the level that opens them
• Generations get flu-style names such as A/Brisbane/12/27 (H3N2), or RTV/M:C/Lagos/12 for Retrovirus
• Each generation is tinted by its mutation, with a corona and orbiting particles that grow every time the mutation is inherited again

Rhinovirus

Rival · Fast

The common cold: a small, fast blue icosahedron that darts around you firing spreads of tiny virions.

• Moves at 150 and keeps a distance of about 140 to 230, circling when in range
• Fires a fan of 4 + generation shots, every 1.65 s at generation 1, getting faster each generation (down to 0.9 s)
• Smallest rival (radius 16); spins fast
• Flees at 1.6x speed, faster than you can run

Norovirus

Rival · Slow

The winter vomiting bug: a slow, cup-dimpled yellow-green sphere that lumbers after you, splattering sticky pools and rings of slowing droplets.

• Moves at 95 straight toward you
• Every 2.4 s at generation 1 (down to 1.4 s) it leaves a sticky clot pool where it stands (it lasts 7 s and slows you heavily while you stand in it)
• Fires a full ring of 8 + 2x generation slowing droplets each time
• The Plasminogen Activator gene stops its clot pools slowing you

Adenovirus

Rival · Armored

The armoured icosahedron: a slow purple shell bristling with 12 fibers, firing rotating crosses of them.

• Moves at 70; the biggest rival (radius 24) with the hardest contact hit
• Has an armor bar worth 50% of its health to break first (explosive damage cracks it faster)
• Fires 4 + generation fibers in a cross that rotates each volley, every 1.88 s at generation 1 (down to 1.1 s)

When rivals appear

Level 9 unlock

After you clear a combat room there's a 6% chance a rival shows up, at a random tier.

• Tier odds: Common 35%, Uncommon 30%, Rare 23%, Epic 9%, Legendary 3%
• The first rival you ever meet is a Common, generation 1
• It appears at least 300 away from you, and its health shows in the top bar as RIVAL · NAME · TIER
• Only one rival is active per run at a time
• Health: 365, scaled by organ, tier (x1 up to x6) and +70% per generation it has survived

Fleeing and the chase

Behaviour

Sometimes, and once when badly hurt, a rival stops attacking and makes a run for the nearest door ("FLEEING!").

• It always breaks once below 40% health; otherwise every 12 s there's a 25% chance
• It flees for up to 6 s at 1.6x speed
• If it gets through a door it hides in the next room: follow it in within 6 s, or it runs one room deeper
• Catch up and it's cornered at the far side of the room ("CAUGHT UP!"), still carrying its wounds
• Once a room lies between you, or you leave its room while it lives, it escapes

Returning stronger

Behaviour

An escaped rival replicates somewhere else in the host and can come back after a later cleared fight.

• 30% chance after each later cleared fight
• Returns one tier higher (up to Prismatic) and one generation stronger: "It escaped and mutated (gen N)"
• Each generation: +70% health, about 8% bigger, +15% contact damage, more and faster shots, and one more rotating halo
• The bounty grows with every generation

Rival bounty

Loot

Defeating a rival claims its share of the host: nucleotides, materials, gear and more, scaled by tier and generation.

• Nucleotides: 10 + 8 per generation, times the tier's loot multiplier (x1 Common up to x10 Prismatic) and the organ's reward scale
• Polymerase Shards: 4 + 4 per generation. Chaperone Proteins: 1 per generation, plus more at higher tiers
• Ribozyme Cores at Epic tier or generation 3+ (in Endless Game Mode; elsewhere they condense into extra Chaperones)
• Gear whose rarity starts at the rival's tier and rises one per extra generation (within the organ's cap); generation 3+ also drops a second piece

Rival Pheromone

Run modifier

A loot run modifier: rival viruses show up twice as often, but cells hit 10% harder.

• Combined with Scavenger it forms Hunting Season: gear drops another 50% more often

Cruise Ship Cluster

Pandemic city · Singapore

A Singapore policy in Pandemic Game Mode: a Norovirus rival in every organ, and rivals can't flee.

• Loot as normal when beaten

Ruby Princess Docks

Pandemic city · Sydney

A Sydney policy in Pandemic Game Mode: rival viruses are twice as common and one tier rarer, for better loot.

• Doubles the appearance chance and shifts rolled tiers up by one

Rival challenges

Challenges

Challenges for hunting rivals.

• Competition, Apex Strain, Only One Survives: defeat 1, 5 and 25 rivals
• Rhinovirus, Norovirus and Adenovirus Rival (defeat 1) and Nemesis (defeat 5) for each species
• Evolved Rival and Ancient Rival: defeat a generation 3 or a generation 5 rival in a run