

Font was very small on my display, running protontricks 659540 winecfg
and increasing "Screen resolution" to 192dpi under Graphics tab improved it

Occasionally out of sync, or catching up, or cutting out.
If you have good eyes, this is no issue. However, the font can be very small and the game has no in-game setting to increase it. The tip in-game on how to do this seems Windows-centric. I haven't yet found a way to increase font size.
I can safely say the graphics were on par with how I would expect it to look on Windows. Ran perfectly and was pretty fun...
Works out of the box, no tweaking needed.
Music volume seems really low, and there are no volume settings in the game. It seems this is just a general problem with the game, even on other platforms, and not something specific to Linux or Proton.
The game doesn't start.
Works perfect
Works great out of the box.
If you bought it on steam it should launch fine through proton. For the best expirience though I like launching warsim.exe under wine.
Under wine I had better Text zoom compaired to with Steam Proton. Both run perfectly either way.
Text is very glitchy and suffers from artifacts
Fullscreen messed up artifacts even more
Much slower than I would expect for an ASCII game
Enjoyable with no game-play effecting bugs
The background music seems to continue running after I have closed the game.
Does not work at all when starting through Steam. Manually running the game in a shell works, but some minor input bugs occur.
Ran with 4.11. Text output is also a little slow, but that could be due to my terrible specs. Other than that I've had no issues.
Fun until the game breaks down
Very frequent visual artifacts and unstable loading that get worse the longer you play the game. Slows down gameplay & makes the game less readable.
Worked great out of the box via Proton, no launch options required in my case.
Full screen / resizing can mess up the text wrapping

Runs perfectly out of the box after upgrading to Proton 4.11-3.

Not sure why the other users are reporting platinum, you literally have to work around Steam and launch it through the console(go to game directory in the console and run "wineconsole Warsim.exe"). Some window resizing issues, some text is is word wrapped and some is not, some font looks jaggy; it may be my system or the game, I have no idea. Aside from that, it appears to work, sound and music play.

Game requires running "wineconsole Warsim.exe" in terminal. Music and sound effects still work perfectly. Don't try toggling fullscreen within the game, it'll just mess up the formatting a bit and then not fullscreen.