GoG homepage > (your name [drop down menu] when logged in) > “Games” > Click on any game in your collection > Download offline backup game installers
You can download installers for whatever systems the game supports – usually that’s just a Windows .EXE installer (+ several .bin files if the game is large). For games intended to run on Linux w/o WINE, you can select “Linux” from a drop down where it says system and it will give you an .sh file.
Deliberately copy snippets of a work you’re interested in as a study – e.g. transcribe it – and experiment with elements you find interesting (rhythm, chords, synths, effects, whatever) in small test pieces to make sure you understand what’s going on. Let the ideas stew for a while and then much later try to use the techniques you learned in a real piece.
That’s what I do anyway.