Interesting map you have there Pineapple. The cave floor texture is quite unusual.
You have got to a great start on your water. I think now you need to darken your pools a bit and make it looks a bit more sinister and shadowy.
The only thing I have noticed is that your cavern wall edges are slightly pixelated (they are 'aliased'). The map would be improved by running a slightly gaussian blur (between 1 and 5 pixels, depending on the scale of your map) on the appropriate layer(s) or layer mask(s) to give the walls a more rounded natural look (anti-aliasing). Hope that makes sense.