An underwater shooter that has a bad reputation, probably because it is too hard for most players. Speaking as someone who has cleared the game-- it's not bad. It is difficult, but don't fault the game if your playing isn't up to snuff. Deep Blue actually sports some really nice underwater visuals, especially for a 1989 release. The scenery has different layers of scrolling that while technically is pretty simple is used well to create a real feeling of depth, and some stages (especially 2 and 4) are just beautiful. One area Deep Blue really shines is the enemy design; the screens shown here don't even scratch the surface of the plethora of different foe you will encounter.
Deep Blue is especially tough because it is extremely hard to avoid getting hit most of the time, and when you do, your weapon downgrades one level. You can pick up powerups for different weapons, but the arsenal is limited. The swirl cutter weapon is the best, especially if you power it up a couple levels. You only have one life, but you have a life meter that slowly depletes as you get hit. If you avoid getting hit, it will gradually replenish itself. I like this, it's a fresh change from the tired traditions of most other shooters. The music is hit and miss. Every stage starts with a unique theme song but then when you reach the middle of a stage instead of a mid-boss, the music changes to a frantic number and you find yourself in a frenzy of oncoming foe. This frantic tune can be a little grating but most of the actual level themes are pretty pleasant and atmospheric. Overall, not a perfect game by any means, but a fun one nonetheless that doesn't deserve it's bad reputation. A must-try for hardcore shooter fanatics.