1 · Getting Started
PROTOCELL is a top-down arena survivor roguelite. You pilot a single escaped lab cell. You move; your weapons fire on their own. Survive escalating waves, grow your cell with mutations, and reach the boss — while keeping your instability from boiling over.
Your goal in a run is simple: stay alive. The deeper goal is to escape Tethys across eight worlds, conquer the Primordial Abyss, and build a colony of ever-stronger cells back in the Lab.
2 · Controls
PROTOCELL is fully playable on controller (Xbox & PlayStation prompts, auto-detected) or keyboard — no mouse required. The game switches mode automatically the moment you use a pad or a key, so it works out of the box on Steam Deck.
Gamepad
Confirm / select
Cancel / back
Reroll cards · Lock cell · Respec tree
Purge card · Discard cell
Pause
Open the Codex
Previous / next tab
Sort / filter (Lab)⌨ Keyboard
(gamepad) or H (keyboard) almost anywhere to open the Codex — the in-game encyclopedia with help chapters, the mutation atlas, the bestiary and DNA recipes. On a pad, press inside a list to search with the on-screen keyboard.3 · The Core Loop
- Move & dodge. Enemies stream toward you from all sides. Your only defense is positioning — kite packs, abuse open space, never get surrounded.
- Auto-attack. Your weapons fire on a cooldown at the nearest enemy. Mutations change how they fire (more projectiles, circle shots, beams, auras…).
- Collect XP. Kills drop XP orbs (and sometimes DNA, coins or catalysts). Walk over them — your magnet range pulls nearby ones in.
- Level up → mutate. Each level offers three mutation cards. Pick one to grow your build, or reroll if you have rerolls.
- Survive to the boss. Waves escalate for roughly ten minutes, then the world's boss appears. Beat it to win the run and unlock the next world.
4 · Instability & Meltdown
This is PROTOCELL's signature gamble. Every mutation you carry has an instability weight. The more power you stack, the faster your instability climbs.
- Rising pressure. Active mutations push the bar up over time; high combos and certain effects accelerate it.
- The threshold. Cross the critical line (around 80%) and you enter MELTDOWN.
- The countdown. Meltdown is a ~20-second timer. The screen pulses red, the music spikes — bring instability back under control before it hits zero, or your cell detonates and the run ends.
How to keep it under control
- Vitality (VIT) raises your meltdown threshold — the single most important survival stat for greedy builds.
- The Vacuole organelle passively drains instability every second.
- Genome recipes and certain meta-upgrades reduce pressure or decay.
- The Purge card appears at level-up: take it instead of a mutation to dump instability.
- Evolutions like Phoenix / Immortality can save you from a lethal meltdown.
5 · Mutations & Evolutions
Mutations (52)
Mutations come in three families — offensive (projectiles, beams, auras), structural (defense, regen, shields) and special (utility, economy, instability). At each level-up you're offered three cards drawn from your unlocked pool.
- You start with 18 starter mutations. The other 34 unlock as you discover them — mainly through the Primordial Abyss.
- Repeated picks level a mutation up, making it stronger (more projectiles, bigger auras, faster procs).
- If the pool is exhausted, level-ups can offer a Purge card (dump instability) or a coin bonus instead.
Evolutions (18)
The build payoff. Bring two compatible mutations to their maximum level and they automatically fuse into an Evolution — a single, supercharged ability with its own signature mechanic: gravitational collapse, seismic shockwaves, devastating freeze, an undying Phoenix, and more. A rainbow banner announces it mid-run.
- Fusions are automatic — you don't choose them, you engineer them by maxing the right pair.
- Evolutions can keep growing (up to level 8) via chest rewards.
Mutation reference — all 52
Evolutions — the 18 fusions
Bring both source mutations to their maximum level and they fuse automatically into the evolution below.
6 · Worlds & Bosses
Eight worlds, each with its own bestiary, a rule-bending modifier, and a unique boss at the climax. Worlds unlock one by one — clear a world's first level to open the next. Every world also offers 5 difficulty levels and an Endless mode (no boss, pure survival).
| # | World | Modifier | Boss |
|---|---|---|---|
| 01 | Tethys Laboratory | — | The Nucleus |
| 02 | Contaminated Sector | Corrosion — passive instability + corrosive puddles | The Swarm-Mother |
| 03 | Sunken Ruins | Resonance — enemies freeze then rush ×2 | The Fossil Leviathan |
| 04 | Primordial Nexus | Primordial Flux — a mutation is periodically disabled; buffs on kill | The Origin |
| 05 | Cryogenic Trench | Absolute Freeze — slow enemies that shatter into ice | The Glacial Sentinel |
| 06 | Sulfur Veins | Extreme Heat — drifting burning zones | The Howling Geyser |
| 07 | Primordial Graveyard | Necrosis — enemies resurrect once at 30% HP | The Animated Ossuary |
| 08 | The Host | Infection — all mutations disabled 5s every 40s | The Beating Heart |
Boss strategies
Difficulty tiers
Each world offers five numbered tiers plus an Endless mode. Higher tiers scale enemy stats and the world modifier, and stack extra bosses.
| Tier | Scaling |
|---|---|
| N1 | Baseline challenge. |
| N2 | +35% enemy HP, +10% damage, +1 mini-boss. |
| N3 | +70% HP, +20% damage, Phase-5 boss, modifier ×1.2. |
| N4 | +110% HP, +35% damage, modifier ×1.5. |
| N5 | +165% HP, +50% damage, two bosses in the finale, modifier ×2. |
| Endless | Infinite waves, no final boss — survive as long as you can. |
7 · The Primordial Abyss
A separate endgame mode — a dedicated descent of 10 layers (100 floors), each guarded by a unique procedural boss (ten in total, no recycling). Unlike a normal run, your progress sticks:
- Best depth reached is saved — you resume your descent.
- Mutations discovered in the Abyss are added to your level-up pool for every mode.
- DNA harvested is banked for the Lab.
The Abyss is the main engine for unlocking the 34 non-starter mutations. Go as deep as your build allows, bank the rewards, and come back stronger.
8 · The Symbiotic Bench
A fourth place to grow — and the home of organelles. From the Colony, enter the Symbiotic Bench: penetrate the ancestral Hosts and harvest the organelles that strengthen your protocells.
- Form a team. Pick a squad of your protocells, then dive into a Host.
- Descend ten levels. Each Host has ten levels of escalating enemies ending in a Host boss; levels unlock as you clear them.
- Harvest organelles. Levels drop star-rated organelles, typed by stat (Aggression, Resistance, Vitality, Velocity, Precision, Affinity, or instability Drain) — the main way to gear your cells.
- Equip them in the Lab. Slot up to 5 organelles per cell and stack types for set bonuses (see The Lab).
9 · The Lab
Your home base between runs — "The Colony". Everything here is permanent and feeds your runs. Most stations unlock as you progress.
Creation
Spend DNA to create a new protocell from scratch. Each cell has a unique procedural look (from a visual seed you can re-roll) and a set of innate mutations and stats.
Breeding
Cross two cells to engineer a stronger descendant. Offspring inherit averaged stats, the union of parent mutations (with level-ups when both parents share one), and a quality tier.
- Ranks: Strain → Sequence → Chimera → Apex. Offspring rank = the weaker parent's rank + 1 (capped at Apex). Chimera and above require diverse parents.
- Costs catalysts + DNA and applies a breeding cooldown.
- Breeding mixes and levels existing mutations — it does not create brand-new ones (those come from the Abyss).
The Feeding Tree
A per-cell growth tree of 41 nodes across four DNA branches plus hybrid keystones:
- Spend DNA by color to unlock nodes — your cell's dominant base gets a discount.
- Nodes give stat boosts and special keystone effects; higher nodes are gated by rank.
- Changed your mind? Respec the whole tree ( / R) and get a full DNA refund.
Organelles
Equip up to 5 organelles on a cell from 7 types, each rated ★ to ★★★★★. Each boosts a stat, and stacking organelles of the same type unlocks growing set bonuses (up to +200%). The Vacuole type drains instability. Organelles are earned in the Symbiosis mode (the ancestral Hosts).
Genome Synthesis
Craft recipes at the synthesis station from your A/T/C/G stock. Each craft stores a charge that can drop as a rare pickup during arena runs — absorb it to trigger a powerful instant or temporary effect (triple projectiles, freeze-all, instability dump, and more). 20 recipes to discover, including secret ones.
Meta-Upgrades, Missions & Codex
- Meta-upgrades — permanent boosts bought with coins between runs (damage, speed, stability, XP magnet, mini-map, feature unlocks…). They apply to every future run.
- Missions — dozens of challenges that reward coins (kills, combos, evolutions, beating each world's boss, genome milestones…).
- Codex — the unified encyclopedia: help chapters, mutation atlas, bestiary and recipes, revealed as you discover them.
Meta-upgrade reference
10 · Progression & Meta
- Coins — earned in runs & missions, spent on meta-upgrades.
- DNA (A/T/C/G) — harvested in runs and the Abyss; spent on creation, breeding, the feeding tree and synthesis.
- Catalysts — rarer drops, required for breeding.
- The Colony — your saved cells. Set one as active to take it into your next run; lock favorites so you never discard them by accident.
Long-term, you're building a stable of specialized cells — a fragile speed-demon for the Abyss, a high-Vitality tank for greedy meltdown builds, a balanced all-rounder for the campaign.
11 · Tips & Strategy
- Movement is everything. You can't out-tank the swarm — you out-position it. Keep moving, keep space.
- Commit to a fusion. Two maxed mutations that evolve beat a grab-bag of singles.
- Respect the meter. Pre-boss, shed instability (Purge, decay, recipes) so a meltdown doesn't end the fight for you.
- Invest Vitality on any build that wants to push power — it directly buys you instability headroom.
- Equip a Vacuole for runs where you plan to go greedy.
- Mind the world modifier. Necrosis means double-kills; Infection means windows with no mutations — play around them.
- Farm the Abyss to widen your mutation pool, then bring that variety back to the campaign.
- Stock genome charges before a hard run — they only drop if you've crafted them first.
12 · FAQ
Is it playable on controller / Steam Deck?
Yes — 100% on gamepad, including menus and text entry, with auto-detected Xbox/PlayStation prompts. The game auto-switches between pad and keyboard the moment you use one.
Do I aim?
No. Combat is automatic — you only move. It's an arena survivor in the spirit of Brotato and Vampire Survivors.
What languages are supported?
English and French (interface and all text). The soundtrack is music only — there is no voice-over.
Are there cloud saves & achievements?
Yes — Steam Cloud saves and 41 Steam achievements (including a Platinum).
Is it finished?
PROTOCELL is in Early Access: already complete and playable end to end, with balancing and more content arriving based on player feedback.