The objective of Galaga is to score as many points as possible by destroying insect-like enemies. The player controls a starfighter that can move left and right along the bottom of the playfield. Enemies swarm in groups in a formation near the top of the screen, and then begin flying down toward the player, firing bombs at the fighter. The game ends when the player's last fighter is lost, either by colliding with an enemy or one of its bullets, or by being captured. Galaga introduces a number of new features over its predecessor, Galaxian. Among these is the ability to fire more than one bullet at a time, a count of the player's "hit/miss ratio" at the end of the game, and a bonus "Challenging Stage" that occurs every few levels, in which a series of enemies fly onto and out of the screen