Underwater looks nice; the top looks more like saran wrap than water, though. :P I think perhaps it has something to do with the degree of contrast between the highlights and lowlights, and maybe the way it folds... it looks thicker than water somehow, there's no sense of it flowing into itself, if that makes any sense. I'm no great pixel artist myself, though, so I can't really be that much help. :(

Any tips on how to improve the top? O:

I agree with Ambient...you really pulled off the underwater effect o.o

I like it overall though

 Surface of the water doesn't seem all that consistent. The underwater part is really neat though.