I have it and honestly it's pretty bad.
At first I was super excited for it as you, but when I actually got my hands on it I was super... disappointed.
The controls are pretty tight and it has relatively good graphics but ultimately the game's boring.
Most of the games few missions (I think there were 7) have you going from somewhere in the map to another, this takes about 10 minutes or so depending on your skill and which sub you're piloting. Ocassionally there are enemies which for the most part can be avoided (which is basically what you do in the whole game, avoid obstacles), and in some missions, a boss. Generally bosses are easy and dull. And after every stage there's a periscope mode which lasts about 30 seconds where you shoot other submarines or boats or whatever, and everytime you sink one you get an emblem which basically boosts your submarine's stats if you select it before each mission (think VC2's tank stickers). Then there's another mode whose name I forgot which is like a dumbed down version of Advance Wars, but it can only be played over local wireless, unless you want to play it against the CPU over and over, which is pretty stupid. If anything it's more like a tech demo rather than a game.