Hi everyone, dev here. I made a real-time minimalistic football game (in the lineage of HaxBall) in time for the championship, and thought to turn it into an actual multiplayer game polished for release. It should run in any browser, desktop/tablet/mobile as well and requiring no sign-up for instant play. If there are no people to fill in the slots (which will likely be the case as it's brand new) you can also choose to start with bots to play against. I tried to balance the bots so as not to be too "perfect" but not totally dumb either, enough to present a fun challenge -- but they'll still hit their own goal occasionally.

From the technical side, physics is run authoritatively on the server, which was my initial design idea (since a lot of these run in peer-to-peer mode). That brings some interesting trade-offs between perceived lag and local prediction jankiness, which is one of the main points I'm interested to hear feedback about. I think I've got a pleasant balance, but of course nothing beats real player testing.

The technical stack is LittleJS for the client and a combination of Python and Rust for the server (for the critical path); happy to detail more in the comments if anyone is curious.

A fun addition while the championship is ongoing: if you register (fully optional) you can create custom rooms with teams in the colourways of the current or up-coming real games; I actually extracted these from the official match schedule PDF for all group games and am quite fond of the results.

THank you and looking forward to any feedback!