The game features four main zones, each with four rounds, the fourth round featuring a boss fight at the end. Other features include the many secret areas and shortcuts hidden throughout the game, accessed using special hidden "warp" portals. On certain later levels, if the player loses their last life due to being killed by a projectile weapon, they will be sent up to a special "Heaven" round. Here, they can either receive a special ending or find the secret route out of Heaven and continue playing the game.