Project S-11

The game is played in a manner similar to a shoot 'em up arcade game. Players control the S-11 fighter, which can freely move across the top-down oriented screen. Waves of enemies come from the top of screen (and occasionally the side) which the player must attempt to destroy to gain points. Players can collect various power-ups, which will make their weapons stronger or give them an extra life. Players will fight a mini boss half-way through a level, and a larger boss at the end of each level.

Source: Wikipedia, "Project S-11", available under the CC-BY-SA License.