Remove colored balls from the board by placing them in the rows (or blocks) of five or more. JOKER balls can substitute balls of any color. When you quit the game the current position is automatically saved so you could continue playing later.
Add one part Space Invaders and one part Galaga, then shake with twist of Asteroids to get AstroRaid, a modern version of an arcade space shooter. Use your missiles wisely and collect power-ups to survive the waves of alien assaults.