Possibly the greater shooter ever, this little gem was found on the TG16 and was an early game to have an extensive power-up system. You had four different weapons, and each weapon had several different stages. You also could get little helper droids. If you cheated, you could get a LOT of helper droids. The game got progressively harder until you got to the last level, which is almost impossible unless you've played through the entire game without losing more than a handful of lives, because dying didn't force you to start at the beginning again as long as you picked up shimmering orbs that were cleverly hidden as useless weapon-change orbs until you shot them or they drifted tot he top of the screen.
Function dictates form. A beautiful game.