Post by Rimacc in Which bonus challenge do you think is the hardest?

Kenney Jam 2026 » Community

Viewing post in Which bonus challenge do you think is the hardest?

Bit late to be handing out advice now that the jam's wrapped, but I saw a few people wrestling with co-op so figured I'd share some stuff.

I actually skipped co-op myself this time. For a physics game, hashing out netcode bugs in a jam timeframe is a nightmare. But if you're set on it, you don't need to stand up your own servers. Both Epic and Steam offer free peer-to-peer connections, so that side of things is pretty much handled for games like these.

For testing, I built an Unreal widget earlier this year that makes multiplayer QA testing way less painful. It launches up to 4 separate PIE processes signed into 4 separate Epic accounts at once, with the Epic overlay enabled on each respective window. And it's not faking anything with null networking, all the traffic actually routes through EOS from inside Unreal, so what you're testing is the real thing.

I keep meaning to release it and I'll get it out one of these days. If that sounds useful, follow my account and I'll post when it's up. Might do a video walking through it too.

Rythim Man4 days ago

Epic and Steam offer free peer-to-peer connections for games hosted on itch.io games? I know Steam gives developers access to their APIs for free, but I thought it had to be a steam game and the user needs to be logged in to steam. How does that work?

Rimacc4 days ago

Yeah you're right about Steam, its P2P goes through the Steam client so everyone does need Steam open and logged in, no way around that. And you do need an App ID, most people just use Spacewar (480) for testing but you'd want your own to actually ship if you plan on a proper release.

EOS is the exception, one of its policies lets players log in anonymously with a device id so there's no account or client they need running.
They made that for crossplatform compatibility.

Worth mentioning all of this is for downloadable builds by the way, if it's a browser game on itch none of it applies, that's a whole different setup (WebRTC/websockets stuff).

Thumbs Up Studios4 days ago

It's 100 bucks to put a game on steam. That's a bit much for a jam game. Yes it is a work around towards server hosting but it's a very expensive one.

Rimacc4 days ago

You don't actually need to pay the $100 or publish anything to use Steam multiplayer, that's the whole point of Spacewar (AppID 480). It's Valve's public test app, and you get Steam's networking + their relay for free, so P2P works without hosting your own servers. Just note it's meant for dev/testing not shipping (everyone shares the same lobby pool so you just make a filter for your own), and players need Steam open. Bit of a shady rep since pirates abuse it, but for jam co-op it's a free, legit way to get real online multiplayer.

Honestly I'd bet Valve would rather have jammers using it than pirates anyway. A jammer who makes something good might actually publish on Steam down the line, so it kind of funnels people toward them.