Put simply, it’s like a translator that knows many of the languages Windows will speak. However, it’s not always fluent in every language it might speak. This is what proton does, it translates system calls into Linux, essentially. It almost always will work, specially with Steam games.
In other cases, it’s game devs making desicisons to disallow use of Linux. Specifically anti cheat. Not all anticheat is disallowed, but game devs could allow it. They just choose not too.
Most games will run just fine on Linux. I’ve switched entirely to Linux and said goodbye to those few online anitcheat games that disallow. Most everything works.
I loved this game when I was younger. I tried compiling this like a month ago, couldn’t get it to work. Made me real sad. Though, I don’t know what I’m doing so, probably my fault. The game is legendary though, sound design, gameplay, etc. Awesome stuff.