Zero Hour is a top view shooter where you control a spacecraft in multiple directions and try to blast and destroy three alien ships at the top of the screen. As you blast them, you will encounter meteors falling down the screen which can be avoided or shot, and other alien ships dropping bombs. If you hit a meteor, alien ship or its bombs then you lose one of three lives. Once the three aliens have been destroyed and the screen cleared of meteors and aliens then you move to a bonus screen. Your ship falls down the screen and you have to land on a landing pad for a bonus score. Two players can play and each player takes it in turns when the other player is killed.