As always, I'm really impressed with the way you create complex backgrounds ! I think it really shows the efforts (or the talent) that were put in the drawing and it creates an atmosphere. Of course we can see the elements of the background were did a bit roughly (The books, the sheets of paper, computer) compared to the rest (The character) but it's not bad since it creates emphasis on the main subject. The technique is really amazing, it looks like a painting ! The spirit thing is really cool, I like the blue light that you added in the girl's hair and the "sparkles". The overall texture of the artwork is pretty ! I think there are some kind of curtains behind the girl, maybe you could have done them more "supple" ? They look a little bit stiff in my opinion. But that's really a detail ! xD
Amazing ♥

(Is it obvious that I don't speak english ? xD haha !)