thanks a lot for a very re-active answer to fix the game on Ubuntu (I did try the game on your link), but I won't install SDL2 and SDL2-mixer, for multiple reasons the first one is that on the https://www.libsdl.org/projects/SDL_mixer/
It's written:
Linux: Please contact your distribution maintainer for updates.,
Thus I opened "Softwares & Updates" it's not there... and in the package manager there are so many thing with "sdl" inside that I have no idea which one is which one -> thus it become a hassle just to play your game.
Also, Once I did install a software witch installed "Timidity" and got problem with the sound, I needed to remove timidity to get the sound back on my computer... and the lib you are speaking about tells us :
Mixer supports playing MIDI format files using software wavetable via an old version of timidity.
This requires you to have a GUS compatible set of sound patches on your system.
I will not install something else other that the things which come with my distro (Ubuntu-MATE to be exact).
7 years with the same distro, same SSD, never ever formatted, rock solid stable -> I won't play Frankenstein now ;)
In all case thanks a lot for your very fast answer, and have an absolute fantastic day.