TAC-SCAN / Sega / Atari 2600
Tac-Scan is a vertical shooter, but the twist here is that you control a group of five spaceships flying in formation rather than the usual solo ship up against the world. That means you've got pretty epic firepower to start out with, but each ship dies with a single hit and the big cluster makes for a bigger target.
Backgrounds shift from blue to black and back as you proceed, but the enemies seem to just be these generic blocky ships that only change color and fire more/faster bullets as the game wears on. You can also pretty much guarantee victory by just sort of waggling the stick left and right a bit and firing madly. Every now and then, the action stops and you'll get some of your ships restored based on how many points you've scored to that point.
The game is an OK shooter by Atari standards, but it'd be better if the action wasn't so simplistic and repetitive. Nice concept though, and good use of sound and flashing visual effects actually give it a very slight level of emotional involvement, as you kind of feel bad watching your wingmen get picked off one by one in your crazy crusade.
* Gameplay Video