Good game. I don't really see the "water" element anywhere, and the sounds of shots being fired quickly becomes too much. Overrides the music. It's also not clear what on earth is happening at first, so I had to restart a few times.
Every time you place a turret there's a noticeable lag spike (from what I assume is the path being reconstructed). It's also not clear what each tower does, nor what tiles are valid for enemies to walk on.