I have a friend with Arch Linux, so I’ll see if I can recreate the bug. Thanks for pointing it out!
EDIT: Bug confirmed! I made this in an older version of Love2D (0.10.1), and the current version (11.1) appears to have breaking changes.
EDIT: Updated for Love2D 11.1. You can download the new Ungrounded-Linux-1.01.zip file.