Click the screen to begin your mission in Alien Space War. Move your spaceship right by sliding the screen or using on-screen buttons. Shoot the descending aliens by clicking the fire button. Dodge enemy lasers to keep your ship intact. Take out all aliens in a wave to move to the next stage. Pick up bonuses to boost your ship's performance. Gain points for each alien defeated and reach high scores to unlock new levels. Stay alert to elite enemies that appear at the end of certain stages.