Mmmyeah difficulty
You could've had a better description of the game-play. Took some time to figure out how it worked.
First level was easy, second level was very difficult.
Also you shouldn't have to start from level one when you lose in level two, that's just annoying. Especially since it took a few shots to notice you had to use the torpedoes there.
Graphics were awesome especially the menu design, although the white shine made some of the text hard to read.
You have a good consept here, if you polish this game a bit it won't go wasted.