The aim of Galaga is to destroy all enemy ships without bringing harm to your own. Move your ship around and target the enemy ships. Your ship’s weapons fire at a constant rate, so you must guide your ship to eliminate the enemy threat completely.
Galaga features a normal game mode (it has 5 levels, each level has missions) and a challenge mode (it has 6 challenges, each divided into three levels of difficulty – ‘Easy’, ‘Medium’ and ‘Hard’). Each level in the normal game mode gets more difficult than the last, allowing you to earn medals on your achievements. In the challenge mode, you have 3 lives and have to defeat all of the enemies. Obtain special powers in the challenges for a greater firepower.
Click and drag your ship across the screen using your mouse. Your weapons will be firing at a constant rate, so do not stop firing at your enemies because they will be coming in from all directions. If the enemy hits your ship first, you will lose that mission and have to restart it. The enemies come in swarms of varied formations and can attack from any direction.