Wii

Zanac A.I.

They didn't make many good vertical scrolling shoot-'em-up games for the Nintendo Entertainment System, but one of the best was Zanac. Originally published for the NES in 1987, Zanac is an exciting space shooter that broke new ground in the genre with its rich weapon options and adaptive difficulty that makes more enemies appear depending on how you play the game. The busy graphics seemed pretty extravagant back then too. Now, this classic shooter is available for the Wii's Virtual Console at a cost of 500 Wii points, and while the competition for shooters on the VC is about as stiff as stiff gets, Zanac still manages to stand out.