The shadow gives a strong impression as well as the white glow. If you didn't use the glow, the main character -Teito- won't look outstanding. IMHO, it'll be great if you try more focusing on Teito. I mean, make the picture of him bigger.
Ermmm... the other suits the theme quite well but the cassette is a bit off topic, I think.
Overall, I like the background color. The "darkness" feeling that implied in your wall suits Teito's expression well.