Playing QIX i can actually make a full second unseparated line on the GBC wich i don't manage on other systems. Like if you go rightwards to the side, up, then leftwards creating a full double line - i can't do that with brick because the d-pad is bigger and stiffer. Can't do it on GBA either, that one too will leave space and be less precise in general.
There is also this game Batman: return of the joker where a boss is shooting baseball balls at you and you have to duck, move forward, duck closing in on the space. With GBC Batman slides leaps ahead but with GB he comes forward much smaller steps, because the command takes more to input because of the finger moving across the big size of the GB and it requiring more to pressure down.