Not bad, but I would suggest some shadows. Nothing too fancy, but it would give the character a little more depth. This is just my opinion.

Lovely painting, and all the effort was worth it. But I would suggest you remove the lens flare, if possible. The drawing is very artistic but the lens flare is very "digital". Overall awsome.

Nice!

I like how it looks. I have few suggestions though:
- the mane and tail should be a bit more dynamic, from what I see the horse is running so thy should blow more in the wind
- there are 2 main problem with the lighting in my opinion. From what I see the light source is on his/hers right so the drop shadow should be on the left (not top down) and should inherit a silhouette from the horse, and 2, I don't quite see the shading on the subject (but I am color blind and only I can't see it... I do see some on the right side but I think it should be more

All in all... looks nice keep it up :D

P.S. I hope this was helpful for you, sorry fro my bad English