1st screen: The segment stacking looks weird. Try to use another segment as hte top segment one. More powerful lighting would be on place too.
2nd screen: Actually looks nice, but I would imcrease the range of the light and change hte colour propably to blue or yellow-ish... just my opinion.
3rd screen: Teh stacking again on segments. They weren't ment to be on top of eachother. Scene is all in all nice, but powerful lighting would be in place here too.
4th screen: The screen looks ok, but everything looks a tad random. And the room is kinda empty and big on sides for my taste. Why don't the legs have a blood puddle if hte rest of teh corpse does?
Well, the screens look ok, my favourite is 3rd now. It looks actually very well set up. The scene is nice, but you heard me up there.

Hope this helps you!