I’m not a game developer but if I were to make a game, the only ideas that come to mind seem to be “I’m gonna remake my favorite game but change these things I didn’t like about it!” but I heard that’s a bad idea usually.
I’m wondering how much change, and to which aspects (gameplay, mechanics, theme, etc), do you think is needed to make a game inspired by something instead of a rip-off?
Not really, that’s usually how games evolve actually. I would personally consider a game a rip-off if it poorly mimics another game, without bringing anything new to the table.