Galaxy Invaders is a modern take on the classic Space Invaders arcade game. The latter was developed in Japan by Tomohiro Nishikado and first launched in 1978 by Taito. It was a 2D fixed shooter game. This application, like its predecessor, is a shooting game where players must defeat enemy forces using lasers while avoiding being destroyed by the alien ships. These alien ships move horizontally on the screen in formation while moving closer to the bottom part of the game window.
To play, the user moves the mouse to the left or to the right to make the fighter ship move. The fighter ship must avoid getting hit by enemy lasers and colliding with alien ships. The player can fire laser guns from the ship by pressing the left mouse button. A large number of enemy ships can be destroyed by launching missiles at them, done by pressing the control key. Every time an alien ship is destroyed, the player gains points. Players must also watch out for power-ups that fall from the alien ships. Players should catch these power-ups using their fighter ship.
Destroying a fleet of enemy ships will bring on another wave of aliens that is more challenging to defeat. The game ends when the fighter ship is hit three times by enemy lasers or collision with another ship, or when an alien ship reaches the bottom of the screen, indicating that the galaxy has been invaded.