The background colors are nice but you didnt put much effort in making it look good other than that..
The maggots look very unreal
Id erase them and create like waves and hils to make it look normal.
The Building looks like its floating
Try adding some extra floor and stuff on the outside so it will be nicer looking.
The whole map just lacks stuff with "Z"..
Maybe ill try it again later and see if there is more.
Now as for the level it self, Id move down the gravityball (if it makes it easyer) and have only one missle launcher on the side of bandage girl, This will make the stage easyer and much more fun to people who just want to try stuff..
EDIT: Megaton hammer?
Thanks =), and I am aware of the looks of the level, I was just eager to see if people liked the level itself. I will address the difficulty of the level and the looks pretty soon. I appreciate your comments.
I adjusted many of the things you suggested but for some reason I can't build outside of the level's perimeter. I thought I could do that but I can't which makes it difficult for me to make stuff on the outside of it.
Edit2: I made the improvements and uploaded the level again.