I like the games art style and music, as said before the connection to the theme is not really apparent but that is not always the most important. Make the game you are happy with that is what mathers.
2 points that sort of bothered me
1) sometimes the cutouts of the monsters didn't seem well done i saw artifacts at what i imagine where the edges of the png.
2) The controls dint feel very good for me it was more like i was sliding on ice than swimming. In a game about swimming that is an important part
none the less a very well done game