Thunder Force III

Screenshots:

Background:
Over 100 years ago, war broke out between Galaxy Union and the Empire of Lone. The Empire had massive weapons and was crushing anything the Union could throw at them. All that changed when a small, but powerful, fighter ship named Styx was unleased. You pilot this versatile craft and must travel to all 5 of the Empire's planets and destroy the forces on them. But your job doesn't end on just the 5 planets, as you will find out...

Gameplay:
The game is viewed from a side-on perspective and is typical to many similar games of the time. You have 5 different weapons which you can collect during the course of the game as well as other powerups. There is no limit on ammunition so you can fire your guns all level, the screen will continuously move forward until you get to a boss.