The current GoG version is 1.22, so it shouldn't work with mono anyway, unless there is a way to downgrade to 1.20 or below...
Single player and local multiplayer with an external controller run just fine for me as long as the swap file isn't being accessed. Whenever swap gets accessed, there is a small stutter. Pretty trivial though. Thanks for this, ptitSeb!
I can't seem to get the screen to show while in minimenu(in the hopes that it will use less RAM than XFCE). The music plays, and the screen goes black for me right now.