Ohh... I really like this!
Twiluna is far and away my favourite pairing, and you've really done it justice. Unfortunately, I don't know anything about painting, so I'm hardly in a position to provide proper critique. However, I can certainly say that I absolutely love what you've done with it. The colours are spectacular, and I particularly love what you've done with Luna's mane and tail. Awesome work!
Would you maybe possibly be okay with me using this as cover art for a fanfiction of mine?