The more rare, obscure, or just a guilty pleasure, the better. Maybe you grew up with it, maybe it’s just the nostalgia talking, any reason is fine.
I’m looking for a new game to play, but I’m running out of games to collect!
My favorite is games for original DMG, but you’re welcome to include Color it’ll advance games too!
Pitman, also known as Catrap in US: https://en.wikipedia.org/wiki/Catrap
It's not really something special or so, but I had it in my youth and used the level editor to build countless levels with my friend. It's a side scrolling puzzle game, with the abiliy to go back in history with a nice backwards animation.