I don't mean the boss area (c11) bat. The first area the character appears in after making a new game has a bat enemy. I thought it was strange it was there, as it was a really strong enemy to fight before even being taught how to attack. You showed yourself testing the bat (then normal enemy) in the f01 map, so I figured it must've been put there by accident. After a few seconds, the bat starts his air attack, but then the game crashes. The entire window just closes. Here's a video. I assume it was just a debug enemy in the f01 map, and that you just forgot to disable it in the final export. It's flight stage probably calls for an object not present in this stage, crashing the game. I see someone also commented about this issue on the windows version, so it's not just a linux port thing.
P.S. In the video the game seems to freeze, but the window fully closes. OBS just freezes the last frame once the program aborts.