Hi! Steam errors in the log are actually expected - for simplicity we publish on itch.io the exact same executable as on Steam. It tries to detect if it’s running under Steam, and if not, proceeds without it, so those errors about Steam should be ignored.
It definitely should not crash though! Can you please find Log.txt file (it should be in the same folder where the game is located) and post its contents here or email it to quyse@kozinaka.com if it’s big (it probably is). Also what Linux distribution you are on? Really appreciate any more info on that.