[2021] Is this game possible to play on linux?

Linux works with Proton but the vast majority of servers will not because the anticheat cannot work in Proton. People have posted servers for Linux players and instructions on how to connect to them in other threads here.

There are a few Linux-oriented servers around that do not have EAC enabled. You'll need to search around to find them as the in-game server browser doesn't help a ton with this.

Originally posted by Capuno: GNU/Linux was a supported platform, the developers made money advertising the game with the SteamOS icon claiming it worked on gnu/linux, but they sadly found it a funny joke to later disable the support, effectively scamming all the GNU/Linux players. Do NOT buy this game if you are on GNU/Linux.

Not a very effective scam if you offer everyone a full refund.