Most co-op survival and builder games have exactly one live world. Whoever hosts holds it; everyone else is a visitor. That's fine until the world needs to move — and a Steam Deck makes it need to move more often, because now even your own two machines disagree about who has the latest copy.
You end up with two questions stacked on top of each other:
- Whose save is current? — the group problem, as old as co-op.
- Which of my machines has it? — the new one the Deck adds.
They have the same answer.
One world, a queue for it
Checkpoint64 keeps the world in the cloud with its full version history, and puts a server-enforced lock in front of it. Only the person holding the lock can push a new version. Everyone else can pull and look, but not overwrite.
Playing a session looks like this:
- Take the lock. Whoever held it last gets told, and it lands in the group's shared logbook, so there's a record rather than an argument.
- Restore the latest version and play.
- Finish, and the new version goes up. The lock frees for the next person.
The Deck doesn't complicate that, because the Deck is just another seat at the same table. Same account, same save, same lock. Taking the world to the sofa is the identical operation as taking it to a friend — you take the lock, you have the world, and the group knows.
The Deck-specific bit
The one thing that would normally break here is where the files land. Your
desktop writes the world to a Windows path; the Deck runs the same game through
Proton and needs it inside a per-game prefix under compatdata, keyed by an app
ID nobody memorises.
Checkpoint64 resolves that on the machine doing the restoring, so the world you took on your desktop arrives somewhere your Deck's copy of the game will actually read it. There's no path to carry across and nothing to configure. The full mechanics are here if you want them, and the two-machine version without the co-op layer is its own post.
What you give up
Be straight about it: this is not a dedicated server, and the world is not online while nobody's holding it. If your group needs someone able to drop in at 3am across four time zones, rent a box — that's the case a rented server genuinely wins.
What it replaces is the far more common shape: five people who play in roughly the same evening window, currently paying €120–240 a year for a machine that sits idle about eighteen hours a day, and still losing an evening occasionally because two people played separately and one save ate the other. The lock fixes the second problem outright, and a Deck stops being a reason the world is stuck on somebody's desktop.
Games this fits
The single-world co-op games where "who's got it?" is a recurring question — Valheim, Factorio, Satisfactory, Palworld, Enshrouded, and the rest of the co-op catalog. Most of them run on a Deck through Proton, which is exactly why the world keeps needing to move in the first place.
Checkpoint64 is on Steam with a SteamOS + Linux build, so a Deck installs it from your library like anything else.
Download Checkpoint64 — it's free, and the free plan is real. No email list, no follow-ups.