Galactic Attack is a top-down shooter game where players control the RVA-818 X-LAY starfighter as they battle against opposing forces. The game features seven levels, each with its own unique environment and massive boss at the end, ranging from fighting in planetary atmospheres to battling over mountain ranges.
The story revolves around the creation of Con-Human, a supercomputer designed to help Earth's governments protect the planet's ecosystem. However, things take a turn when a cloned human is linked to the system, making it sentient and eventually becoming insane, causing natural disasters that wipe out nearly all of mankind. The remaining survivors flee to space and develop colonies on other planets, with Con-Human assembling an armada to destroy them.
The gameplay involves flying around each level, using the primary laser weapon to destroy enemies on screen. Players can upgrade this weapon by collecting "L" icons while destroying enemies, allowing for increased firepower. Additionally, a secondary lock-on missile launcher can fire at eight different ground enemies simultaneously.