Co-op games like COS-MOS
Below are 8 cooperative Steam games similar to COS-MOS, ranked by player overlap and content similarity. Every pick supports cooperative play — online co-op, LAN co-op, or shared/split-screen — so you can play with friends right out of the box. imho.run pulls from the same Steam category data Valve uses internally, so "Co-op" here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like COS-MOS page.
Ranked picks
- 1
SplatStick
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Massively Multiplayer with COS-MOS.
A stickman fighter where physics does half the work. Punch, grab, throw your opponent off the edge the more damage they carry, the further they fly. Nine modes, from deathmatch and tower sieges to football and hot potato. Two on one keyboard, or six online.
- 2
Sky Pirates
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Adventure with COS-MOS.
A co-op game where you play as pirates sailing the skies aboard a flying ship, searching for treasure and growing ever richer. But beware… wealth attracts greed!
- 3
F.A.G.E.N.
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Casual with COS-MOS.
F.A.G.E.N. is a 2–4 player co-op comedy-horror game where every sound you make affects your nose. Run a bizarre restaurant by day, collect the F.A.G.E.N. resources demanded by your boss at night, and try to reach the goals they set before you get fired.
- 4
Drunkslop: Pub crawl COOP
Online Co-op alternative to COS-MOS — playable with friends. Shares Adventure and Massively Multiplayer with COS-MOS.
DRUNKSLOP: 100% Chaos. 0% Hangover. The only co-op where getting totally wasted is the actual win condition. Scavenge for cash, chug drinks, make terrible choices, and somehow clutch it out. Strap in, it’s a long-ass night.
- 5
Ship or Burn! Coop express
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Adventure with COS-MOS.
Someone's order is on fire? At least the train keeps going! Load up the parcels, toss everything into the furnace, and off we go! Zombie consumers after your cargo? Into the furnace! Online co-op for 1–4 players about delivery, chaos and greed.
- 6
DADCORE
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Adventure with COS-MOS.
DADCORE is a chaotic 4-player co-op dad simulator where being a dad is survival horror. Do chores, save money, sell backyard junk, and defend your home from Taxes, Bills, Inflation, and the Mortgage. Every bullet costs money, so spend wisely.
- 7
ZONE L.O.S.T.
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Adventure with COS-MOS.
YOUR BODY IS YOUR WEAKNESS. A four-player co-op horror game that puts you in the shoes of the chief scientists of a research facility. Your sole objective is to carry out the self-destruct plan and escape the facility.
- 8
HANDSUP
Online Co-op alternative to COS-MOS — playable with friends. Shares Action and Adventure with COS-MOS.
Escape a vertical nightmare with up to 4 friends using physics-based parkour. Equip Magic Rings to customize your climb. Don't let go, just keep your Hands Up.