I always thought a MOOG pinball would be cool, sound powered by a Moog Synth. You start with a basic beat, completed goals and targets build a techno synth song. Completing harder goals unlocks new songs or new sounds. The Moog Pinthesizer. (You could have a mini keyboard for a lockdown bar that allowed you to change the key or have a mini game where you play a song sequence, like Axel F by Harold Faltermeyer)