Unlock schedule
New Mechanics, One Per Level
A new save isn't buried in systems on run one. Each in-run mechanic unlocks for the whole save when any virus reaches its level (Hosts & Host Traits: 2 finished generations; the Cytokine Storm instead switches on from the fourth organ at any level), then is introduced on its own: a NEW MECHANIC UNLOCKED card that pauses the run the moment it first shows up (right as the organ starts for tumors, room tiers and immune learning), and except for the Cytokine Storm it's guaranteed to appear in that organ. Only one is introduced per run; the rest wait for later runs. Hosts & Host Traits is introduced on the host reveal before you land instead.
The first few cells you kill in a fight can drop an elemental power-up: a few seconds of a big effect. CRISPR, the rarest, makes you invincible.
Short bursts of elemental power, and the rare CRISPR.
Fun fact: Different power-ups run at the same time, and they follow you into the next room.
Power-ups in the Codex
Trade-off altars, receptor puzzles and event rooms (siege, gamble, harvest, refuge), marked with coloured borders on the minimap.
Rooms that aren't straight fights, outlined in colour on the minimap.
Fun fact: Refuges are worth remembering: you can come back to one when Detection gets high.
Special Rooms in the Codex
Cells can come in stronger tiers (green, blue, purple and up) with affixes like Shielded, Swift or Vampiric; they hit harder and drop better loot.
Stronger versions of normal cells, ringed in their tier colour.
Fun fact: Elites drop better loot, including gear.
Elite Cells & Affixes in the Codex
Dormant Virions can drop from tough cells; each one is an extra life.
Ways to survive a killing blow.
Fun fact: The orange hourglass badge on your virus's portrait shows how many extra lives you have.
Extra Lives in the Codex
When Detection fills to 100, elite hunters follow you from room to room until you destroy them.
The immune system's elite hunters (cytotoxic T cells), dispatched when Detection reaches 100.
Fun fact: When a pack is destroyed, Detection drops to 0 and stays frozen for 20 seconds: that's your breathing room.
Killer T Cells in the Codex
Most organs grow a tumor that spreads and sends assassins; destroy it for a big reward or it follows you to the next organ.
Cancer growing in the host while you're there, and what happens if you leave it.
Fun fact: Kill tumors early: they only get worse, and they follow you if you don't.
Tumors & Metastasis in the Codex
Each organ gets its own hazards: cilia, vents, clots, fibres, pits and the occasional drop shaft.
Parts of the tissue itself that can hurt you or help you.
Fun fact: Most hazards hurt cells as much as you: lure them in.
Hazards in the Codex
Other viruses want this host too; beat a rival for rich loot, or chase it before it escapes and returns stronger.
Other viruses competing for the same host.
Fun fact: Rivals don't lock the doors, so running is always an option.
Rival Viruses in the Codex
When Detection stays high, the host may take antivirals, a vaccine booster or interferon. Walk out of the room to escape the dose, or survive it for a reward.
The host feeling sick and taking medicine when Detection is 75 or more.
Fun fact: Walking out of the room escapes a dose; surviving it pays out.
Treatments in the Codex
Rooms roll a tier shown as a coloured minimap border; higher tiers carry more boons and more drawbacks.
Every room rolls a tier, from common to prismatic, with boons and drawbacks.
Fun fact: Check a room's border colour on the minimap before you walk in.
Room Tiers in the Codex
From the fourth organ on, if your build gets too strong, the storm meter fills and the immune system sends crimson adapted cells that resist your build.
The immune system's answer to a runaway build: when you kill ordinary cells too easily, or barely get scratched, it starts sending cells built to resist you.
Fun fact: Kill the crimson ones first: they're the ones keeping the fight fair.
Cytokine Storm in the Codex
Lean on one shot type and cells start resisting it; the immune level rises with every organ and Killer T pack.
Adaptive immunity: the host studies how you attack and grows up as the infection goes on, so the same trick works less and less.
Fun fact: Mixing your shot types (or switching with Antigenic Shift) keeps it from ever pinning you down.
The Immune System Learns in the Codex
Each host gets a genome of hidden traits, good and bad, revealed when you infect it. Rarer hosts have stronger traits and richer rewards.
The person or animal you infect at the start of a run.
Fun fact: Rarer hosts have bigger effects and pay more nucleotides.
Hosts & Host Traits in the Codex
Early runs use smaller rooms and shorter fights; they grow to full size as your best level nears 12 and your lineage nears 6 generations.
Each organ is a map of connected rooms, different every run.
Fun fact: Bigger rooms hold more cells, spread around the whole room, and always fight in several waves.
Rooms & Waves in the Codex
