Co-op over Steam
Host a lobby, invite friends from the overlay or the in-game browser, and play through Steam's own peer-to-peer networking. LAN and solo-with-bots work without Steam.
What you're in for
Random maps, every run
Every level is generated on the spot: rooms, corridors, open streets, dark corners and safe rooms. Four levels per run, ending in a finale with three waves and an extraction.
Classes, XP and perks
Medic, Gunner, Scout or Engineer, each with an active ability. Kills and rescues earn XP; every level-up lets you pick one of three perks that last the run.
An AI director
Build-ups, hordes and special infected are paced by a director that watches how your team is doing, so no two runs feel the same. Downed? A teammate can pick you back up.
Pick your survivor
Medic
+50% healing. Keeps the team up.
Q · Med Field — heals every ally within 6 m for 6 seconds. Cooldown 45 s.
Gunner
+30% ammo, 20% faster reloads.
Q · Overdrive — 6 seconds of rapid fire with instant reloads. Cooldown 40 s.
Scout
+15% move speed. Fast and nimble.
Q · Dash — an 8 m burst with half a second of invulnerability. Cooldown 12 s.
Engineer
+25% from pickups. Builds defenses.
Q · Sentry — drops an auto-turret for 20 seconds, 30 damage per second, 12 m range. Cooldown 60 s.
Level up, pick a perk
Tough · +20 max HP
Swift · +8% speed
Deadeye · +15% damage
Headhunter · crits
Vampire · HP per kill
Explosive rounds
Second wind
Juggernaut
…and 11 more, some class-only
Meet the infected
Shambler
Slow, endless, and never alone.
Runner
Fast. Hears you reload.
Boomer
Pops, hurts, and calls the horde.
Hunter
Leaps from 8 m away. Shove it off.
Brute
600 HP of bad news. Bring the shotgun.
Download
Free, version 0.1.0. Unzip and run — there is nothing to install. Everyone in your group needs the same version.
macOS
Apple Silicon & Intel · macOS 11+
Download .zip63 MB
First launch: right-click BITROT.app → Open. The app is not notarized by Apple, so macOS asks once.
Windows
64-bit · Windows 10 or 11
Download .zip40 MB
First launch: SmartScreen may warn about an unsigned app. Click More info → Run anyway. Keep all files together.
Linux
x86-64 · OpenGL 3.3
Download .zip31 MB
Run ./BITROT.x86_64 (chmod +x if needed). Keep all files together.
Requirements: any 64-bit machine from the last ten years. The game renders at 480×270 and scales up, so integrated graphics are fine.
- Online co-op: the Steam client running and logged in. The game itself is not on the Steam store; it uses Steam's free developer test app, so everyone can play without buying anything.
- LAN and solo: no Steam needed.
Playing with friends
- Everyone starts Steam, then launches BITROT. The menu shows STEAM: your name when it's connected.
- The host picks PLAY WITH STEAM → HOST LOBBY, public or friends-only.
- Friends join via LOBBY BROWSER (it lists only BITROT lobbies), FRIENDS' LOBBIES, or an invite sent with INVITE FRIENDS from the lobby.
- Pick a class, press READY, host presses START. Up to four survivors; the host can fill empty seats with bots.
Good to know
While BITROT uses Steam's test app id, Steam shows you as playing Spacewar and the friends-list Join Game button won't launch the game. Use the in-game lobby browser, friends list, or an invite while the game is already running.
No Steam? On the same network use LAN → HOST and LAN → JOIN with the host's IP (shown in the lobby). Over the internet, the host forwards UDP port 27050.
Down at 0 HP? You bleed out in 30 seconds unless a teammate holds E on you. Dead players come back at the next safe room.
Controls
| Action | Keys |
|---|---|
| Move / sprint / jump | WASD Shift Space |
| Fire / reload | LMB R |
| Melee shove | V or MMB |
| Use: pick up, revive, heal | E (hold) |
| Action | Keys |
|---|---|
| Class ability | Q |
| Flashlight | F |
| Weapons | 1 pistol · 2 primary · wheel |
| Chat / scoreboard / pause | Enter Tab Esc |
FAQ
Is it really free?
Yes. Download, unzip, play. There is no account, no launcher and no in-game purchases.
Why does Steam say I'm playing "Spacewar"?
BITROT is not published on the Steam store yet. It talks to Steam through Valve's public developer test app (id 480), which every Steam account can use. Lobbies, invites and networking are the real thing; only the name Steam displays is off.
Does it run on my machine?
Almost certainly. It is a pixel-art game rendered at 480×270 and scaled up. It needs a 64-bit OS and OpenGL 3.3 (or Metal on macOS), which any computer from the last decade has.
My friend has a different version.
All players must run the same build. Check the version in the main menu footer and grab the latest zip from this page.
What is it made with?
Godot 4.7 and the GodotSteam extension. Every texture, sprite, sound and even the font are generated by the game's code at startup — there are no image files in the download.