I have to say that your drawing captures the feeling that is expressed in the famous scene in the said movie; like Fionna here, who is quite scared riding a magic black carpet in the night sky while Prince Gumball tries to calm her down by holding her tight, just like in the movie. Cake here looked amazed while watching the two, like the viewers today.
It's a magnificent sight, I would admit. The colors, ambiance, harmony and all are great. But my suggestion is to make the scene (light) dimmer, for I believe it was set in night time.