I agree with Brandon's perspective on this one - that's a really cool unique way to look at it!  But this one kinda looks like a 'reverse on glass' to me.

nice, it reminds me of a leaf floating in a pond, but the leaf is the entrance to the universe.

Agree with TK, needs more black shading and more layering, but overall a good effort.

The "cave" could use a bit more black/ shaded areas.