The game crashed upon opening. I downloaded it and tried opening with terminal. It gave me the error "./GetItBack!: error while loading shared libraries: libopenal.so.1: cannot open shared object file: No such file or directory" I installed libopenal and tried again. "./GetItBack!: error while loading shared libraries: libGLU.so.1: cannot open shared object file: No such file or directory" I installed libglu1-mesa and tried again. "./GetItBack!: /lib/x86_64-linux-gnu/libm.so.6: version `GLIBC_2.29' not found (required by ./GetItBack!)" I haven't had any luck past that point. It may be because I'm running Debian 10.
So, i did a bit of research (i'm not familiar with Linux) and i found that the problem is indeed linked to the version i used to compile the game (20.04), which use GLIBC_2.29 that you don't have on Debian 10. So i set up a virtual machine of Ubuntu 18.04, and compiled the game with it : now it should be playable on older versions! I put a second zip to download above, can you tell me if it works? Also, thanks to your comment i realised that 2 dependencies are needed in order to run the game (libcurl4 and libopenal1) and added them to the install instructions!