Seeking Critiques on 3d lighting for Animation

Hey all! I'm working on an animated piece for my demoreel for graduation, and I need some advice on the 3d lighting.
I'm not tremendously great at lighting, so I'd appreciate comments for those who are willing to give them! (Thanks in advance!)

Here's a link to the piece; it has several examples.
I just need to know what works, what can be fixed, what to keep- etc.

http://katoma.deviantart.com/art/Background-Lighting-Changes-68624478


Thanks again!

-Jen

Program used: 3d studio Max