"Marble Madness" is another game that would have been incredible on 7800. Especially if they offered a track-ball version. Or 5200 even, which had the excellent track-ball controller readily available. In fact, why no 5200 Crystal Castles??? Damn it, Atari! There's one great feature of the 5200 and that's how many games it had that supported the track-ball correctly. Space Invaders with TB is such a trip, for example. Even clunker games like Super Breakout become something special with that controller.