Forced scrolling vertical shooter with neat touches. This is one of the earliest examples of proximity triggered enemies, where the ship that travel horizontally don't seem to move until you get close enough. It's also refreshing to have an actual health meter represented by the heart rate monitor at the bottom of the screen. One miss here is that you don't really need to shoot the enemies to make your way through the maze. By the time you clear many of them, you'd be flying past them anyway so you can focus on just avoiding them instead.