I'm sorry for the lack of details, I submitted last minute. Anyway, the zip contains the source code, to play the demo one must load the asd file (open common lisp repl in the extracted directory, then eval (load-asd "absolute/path/to/game.asd")), after which you'll probably have to add the trivial-gamekit repositories (see https://borodust.github.io/projects/trivial-gamekit/#installation-and-loading ). Finally you can (ql:quickload :game) and it should start. Probably not worth it since there isn't much going on, but the rules encouraged submitting unfinished projects.
The game itself is just a demo of platformer mechanics. You can move the character around with wasd (or arrow keys), also space turns gravity on and off. The idea was that you're using magnetic boots to walk on your spaceship, because you have to fix it. So yeah, try to get on the higher platform, if you manage to, you win!
Oh well, better luck next jam