Alien Invaders from the Planet Plorth is a shooter game in which the player moves sideways trying to dodge enemy bullets. The player is positioned in the center of the screen with top and bottom enemies moving closer towards the player. The game automatically ends if an enemy reaches the center of the screen. Shoot all enemies and move on to the next level. On every 10th level, you will have to defeat a more difficult "boss" enemy that shoots orbs and brings down a beam toward the center line. You lose a life if one of those orbs or beam hits