Any Palm OS hardware
Palm OS 3.5

Drive this Space Ship through a galaxy populated with enemy ships. Shoot to destroy the enemy space invaders and save the planet. The invaders\ ships move leftwards/rightwards across the screen. Each time they reach its end they come one step nearer to your position. Your aim is to fire at them until you destroy them. At the bottom of the screen there are several defense walls that protect you from the invaders\ fire.... but they can be destroyed too if they are hit. At the start of each game you have five lives. Be aware of the fact that there are four types of enemies that you are going to eliminate. Some of them die at the first shot but there are strong ships that have to be hit 3-4 times until they are destroyed. A bonus-ship fly across the screen from time to time. Take avail yourself of the bonuses that it will give you if you manage to hit it.