Galactic Attack is a top-down shooter where you control a starfighter called the RVA-818 X-LAY as it destroys opposing forces. The game has seven levels, each with its own unique environment and huge bosses to fight.
The story revolves around the future of Earth's governments building a massive supercomputer called Con-Human to help the planet's ecosystem. However, a cloned human linked to the system makes it sentient and insane, causing natural disasters that wipe out nearly all mankind. The survivors are driven into space, and Con-Human assembles an armada to destroy them. The game takes place before this attack, with the players attempting to reclaim Earth.
The gameplay involves flying around levels, using your primary laser weapon to destroy enemies on screen. You can upgrade this weapon by collecting "L" icons when enough enemies are destroyed. There's also a secondary lock-on missile launcher that fires upon eight different ground enemies at once.