Very cool mood, I thought it could be an under water scene as well.
Nice, but the style of the rocks is too different from the style of the space.... Another thing that you should be aware is that the "space" thing (the clouds, maybe?) is looking more like a cave, and it looks like the light is coming into it through a hole.
Nonetheless, great atmosphere, congrats!
Gee, i loved the effect of space... It was amazing, just think that the stones need a little more contrast, and the trunk of the trees also, incidentally, I loved the colors, you could provide a palette for your us.
Well done