The grid doesn't help, as two subs can be a different number of squares away and hit or miss, depending on which one is going horizontally and which one vertically. The concept of the gameplay has potential, and you did get some interesting puzzles, but there are more problems than props.
The music gets stale fast, and the premise is screwed. Clean up by trashing them? Try giving them an 'enemy' skin and saying you've taken over their navigation!
Wanna clean the oceans? Blow stuff up underwater and let it sink to the ocean floor. No seriously, it's not a bad time waster. I got to level 15 then I got bored though.
The great thing about this game is the difficulty. It gets much harder pretty quickly and I was drawn in before I found it too easy to be worth the time.
The really annoying part is how the game restarts itself. I spend a little time rotating submarines, fail, then I am back at square one since the directions were reset. Don't you think that's a little annoying to have to reset submarines every time? Some times, there are submarines that we would think were set perfectly. You could at least have a reset button to reset directions if a player thinks it's helpful.
Had fun.. i just wish the link at the bottom left was a little smaller, it gets very close in the way sometimes.