Very impressive. I like it alot, and the music is just amazing!

From what I saw (video and screenshot) the art and sound are Ok. But overall it seems empty and kind of boring. Sorry if I'm a bit blunt, but I have the impression of having already see this kind of game multiple times over the net. I don't think there is something more in your game.

Here is some remarks :

- Story of the level : I would have tried to make a mirror between the two worlds. For exemple where there is a tree in the light, there is a antenna in the dark world. This should bring more coherence and make the world more interesting.

- Empty : having only a background and some platform is ok for a flash game, but with a complete engine it should be relatively easy to add more element, create a world over your platform.
- Repetitive : it's dependant from the previous point but if the mechanics of passing from a world to another can be interesting, I think it quickly reach its peak of interest. Why not being able to pass through multiple worlds? For exemple you have the green orbs who allow you to pass to the light world. In the first part of your level you have to get to the red orbs, which allow you to go to the red world. And you have to go to the red world to reach the exist.
- Not a flash game : you said that in one of your announcement. First, I don't think there is anything wrong being a flash game. Secondly, well it is typically the kind of game you could find on the likes of Kongregate, even though you used a 3D engine.

I hope those various comment can help you and good luck :D

The game looks amazing! I really love the art!