Galacta

This uses the same basic concept as Galaxian, Space Invaders, Galaga, etc. as you are a spaceship on the bottom of the screen shooting aliens on the top. However, this provides greater control of the weapon (you can make your bullets go in many directions), and it keeps you on edge, quick reflexes are critical, if you blink, you might miss something (or lose). There are also some powerups like a temporary shield.

If you like Galaga or similar games, download this for more fast-paced action.