The game is a side-scrolling shooter, with you controlling the submarine as it explores the underwater caverns. The game follows the same "if it ain't broke, don't fix it" approach of countless shooters before it, although there are several nice innovations. For example, you can launch a small submersible called "Jason" that will help you to reach confined spaces in the game. This is useful for collecting hard-to-reach power-ups, for example. If you like Pea Shootin' Pete or well-designed shooters in general, you will like this fun, unassuming underdog that boasts much higher production values (and a greater number of levels) than its shareware status may suggest. Recommended!