Plutonium

whenever i use them it seems to just close the game, but you can launch zombies directly using the bootstrapper and some arguments. the only issue is that the only tutorial ive found for this uses LAN mode, so you cant play online. the tutorial was made for steam deck though so if youre not using it it might be a little confusing but it worked on my windows laptop.
(heres the tutorial btw look at the "Adding a Game and a Mode" part:https://forum.plutonium.pw/topic/40011/setting-up-plutonium-on-the-steam-deck-and-linux-lan-only)