the spikes are REALY good, I like the contrast between the light crystals and the black rocks, but as people have said the water area looks bad in comparison, add crystals under the water but make them darker so theure barely visible, that wil amke them look like their under water.
I;d add a shadow maybe to the necroplois aswel, make it look like the rocks and stuff are rising out of the water, right now it looks like some ones built a neat little pond in the middle of ragged rocks. You need something to beark up the texture patern of the water.