I noticed that the GOG version of Loop Hero stopped launching for me a while back and other Linux users have reported similar issues.

When run from the terminal you'd receive an error along the lines of:

libssl.so.1.1: cannot open shared object file: No such file or directory

With some help from GOG Support and a bit of research I was able to pull together 7 different 32-bit libraries that Loop Hero still looks for, but are outdated, at least as of Linux Mint 21.3 (I think this will only work on amd64 distros).

Just toggle root access, and drop these libraries into /usr/lib/x86_64-linux-gnu and Loop Hero should launch properly.

Files: https://github.com/IfGremlinThen/CustomPatches

PS: PulseAudio doesn't want to pick up any audio from the game for me, but I don't know whether it's related.