Castle Crashers launched on Xbox 360 in 2008. Thanks to Microsoft's backward compatibility program, it runs natively on:
No separate purchase needed if you own the 360 version digitally or have the disc (disc acts as license key on One/Series). Digital owners can download directly from "My Games & Apps" → "Ready to Install."
The Behemoth (developers) have confirmed a new game in the Castle Crashers universe is in development, but no platform exclusivity or release window has been announced. It will likely target current-gen consoles and PC.
If you haven't played it, it's one of the best couch-co-op experiences on Xbox—past or present.