The Unicorn

I think you're onto something great here - I love the way you have a foreground and a background to surround your main character and to frame him, too. I also really like the blue-cyan lighting.

What is a bit strange is that even though you have this strong light going, the horse is pretty much without shadows - I can see none on his underside besides the ones that are there naturally, but I think they'd need to be way stronger than that. Same goes for a cast shadow of the horse: if the light is this strong, it'll throw strong shadows as well (as you did for the glowing butterflies in the foreground). In the same direction, the glow on the horses belly should be less prominent. It's good to get some colour on an object from its surroundings to account for bouncing light, but I don't think it would glow that much.

And lastly, I'm a little put off by your background light source as it looks like there are two - one from above and one from the right/top... rays of light coming from the moon or sun should be almost parallel, because the source is so far from us.

I hope this helps you out a little, keep it up!