You might also call it Endless Ocean 3: Treasure Hunter.
Early reports suggested that Dive: The Medes Island Secret would be something akin to an underwater Metroid game, but after sitting down and actually playing Dive for awhile, I can safely say that it's almost nothing like Metroid, but instead very similar to the Endless Ocean games. Here, though, you need not worry about cataloguing every fish in the sea or studying polar bears. Instead, Dive takes the exploration and treasure-hunting aspect of Endless Ocean and runs (swims?) with it.
The control scheme is unique and pointer-based. You aim the pointer where you want to move, and hold B to make your character swim in that direction. Double-tapping the B button will result in a quick burst of speed, but at the cost of one bar of your oxygen meter. Pressing and briefly holding the A button while aiming at a dangerous fish or invertebrate will make your diver whip out his "tranquilizer" spear gun and run the offending creature through. Pressing left on the D-pad toggles your flashlight, and pressing right toggles the area map. The control scheme is simple yet effective.
The main goal in the game is to find treasures scattered around every map. Each map has up to and sometimes exceeding 40 small treasures and up to three big treasures. These treasures are usually hidden in crevices, guarded by aggressive marine fauna, and may require liberal use of your spear gun to obtain. Each treasure, big or small, nets you a certain amount of money, which you use between missions to upgrade your diving gear. These upgrades, in turn, are used to access areas you might not have been able to reach in previous areas. That is the only aspect of the game that may resemble Metroid, although it's still a stretch; your upgrades never actually change the way you fundamentally play the game. They just give you more depth, health, speed, or spears.
Gamers who enjoy exploring every nook and cranny in games like this will find a wealth of treasure and upgrade their gear fairly quickly. I was almost completely geared up by the fourth level, lacking only a few of the final upgrades. Thankfully, the game steadily ramps up in difficulty, so you will never feel overpowered. Difficulty is measured in terms of aggressive marine life (there's plenty) and scarcity of oxygen and spear gun refill items. In general, the deeper you go, the fewer refills you'll find, and the more careful you'll have to be.
You won't have to rely purely on your instincts to find treasure and refills, though. Your diver is equipped with a compass that, when in range, shows the general direction of small treasures (red), large treasures (yellow), and refills (green). Because the level design is often layered, with lots of parallel tunnels and branching caves, you may be able to see a treasure above or below you that requires a lengthy detour to actually nab.
Dive is a beautiful game. The ocean floor crawls with ambient life, the lighting is spectacular — especially when you're deep underwater and your flashlight is on — and the animals around you move with believable, and sometimes nefarious, purpose. The colors pop off the screen and everything animates smoothly. Unfortunately, there aren’t a lot of differences in terms of assets. Almost every stage in the game has you traversing the same rocky caverns, trying to avoid the same kinds of fish. Sure, there are changes here and there, but overall, it's very much a situation similar to last year's otherwise-excellent NyxQuest (strangely enough, they also run on the same engine). Granted, the developers do a good job trying to hide this fact, as the deeper you go, the darker it gets, and the less you notice little details. At a certain depth, the game almost takes on an eerie silhouette look because there's so little light. Still, I would've liked to see more variety in the locations and the assets within.
The only real downside to Dive is its musical score. I can count the number of distinct musical tracks on one hand. The upper levels of the sea are dominated by a largely upbeat, adventurous tune that repeats too often but gets the job done. As you reach a certain depth, the music changes to become very minimalist and spooky. It's a great effect that's sadly used in every area of the game. You certainly won't find the varied, grandiose score of Endless Ocean 2 here, nor should you, on a downloadable title,, but a bit more variety would have been appreciated.
However, Dive's few faults can't sink its many successes. The game is fun, challenging, and gorgeous. If you like the Endless Ocean series or games that emphasize exploration, this one's for you.