Gameplay Galaga

Gameplay
Galaga is a sequel to Galaxian and has similar gameplay. The player controls a spaceship (which can move only right or left) and shoots at swarms of incoming insect-like aliens which fly in formation above him and occasionally swoop down to bomb him in a kamikaze-like dive. The enemies in the top row will sometimes dive with one or two escorts. Enemies which survive a dive will rejoin the formation from the top. When all enemies are destroyed, the player moves on to the next level.

The three types of enemy each have a different score value. A blue enemy is worth 50 points in formation and 100 when attacking. A red enemy is worth 80 in formation, 160 when attacking. A boss is worth 150 in formation, and its attack value depends on whether it is accompanied by red escorts: 400 points if alone, 800 with one escort, and 1600 with two. This point value is determined when the boss's attack is initiated, so shooting escorts before the boss (or missing them entirely) will still earn the higher point values.

A "rapid fire" chip is available, replacing chip 3J on the original Galaga CPU board. It allows for a continuous stream of fire, as opposed to the stuttered firing limitation of the stock 3J chip.