Ok, I guess you didn't understand what i was trying to say
What I meant about the cave was that it should look more organic. It helps to imagine how the cave was actually formed at its creation. 'God' didn't create a box and make spikes coming off the surface and call it a cave. That's what you have. Caves are formed over time by nature. It might sound overkill, but it isn't, one bit! A more simplified diagram is at the bottom, side view.
The mushrooms are a cool idea for a lightsource, but make sure that the colour of the light is reflected by it's surroundings (the spikes should be 'reacting' to their presence). not having this blending-like effect causes an anomaly (an eyesore! the first thing your eye goes to, useful if that's your focus, which in this case it isn't, it is simply a detail). This also goes to the beam of light coming in from the 'roof', it's a white light, but i don't see any reflection of white light in the room. I'm not positive, but I think the white light would also turn a bit red from the surroundings aswell.
These details will make for a more natural feel.
I admire your efforts to make a 3d film, you're a step further than myself. I will continue to provide you with feedback if you want it, I enjoy watching this project and would like to see it come to completion.
-ProAni