Can you try again? (version 3)
Version 2 worked fine on Arch when we tested it, but apparently only when launched from the itch app.
EDIT: I didn't make any changes to the game beyond adding a couple more deps into the libs folder.
EDIT2: Keyboard controls are really weird, that's why we added SDL2 gamepad support with more natural controls at the last minute. SDL won't return keyboard events for a non-SDL window though, so grab your gamepad if you've got one.