You have to install löve (version 11.1) (maybe your package repositories have it already?) then download the .love file and run it with löve!
love Spacetris.love
Is that a compatebillety thing like Steam-play's Proton thing? Isn't really clear when I read the website. It says it's a framework for making 2D games. hmmm
löve is a framework for making games using Lua. And you can run .love files with it too. On Linux that is afaik the simplest option to run löve games
Cool!