Galaga is a fixed-shot RPG. The player is in charge of the single starship at the bottom of the screen. Its job is to stop Galaga's forces from killing all of humanity.
The Galaga formation flies into the screen at the start of a game. In each stage, there is a group of about 40 enemy units. To get an edge in the fight, you need to kill as many of them as possible before they finish their formation. Bosses, Guards, and Grunts are the three types of enemies that make up Galaga's troops. As the game goes on, the enemies start to fly in different ways and use special formation attacks.
If the player's space fighter is taken by an enemy, it will be held by Boss Galaga. However, if the player defeats Galaga, they can get back their captured space fighter and enter Dual Fighter mode. In this mode, the player has twice as much firepower and can kill foes twice as quickly. However, the spacefighter they are controlling also doubles in size, so they need to be very good at steering it away from enemy attacks.
Have fun and good luck!