It would be nice if we had placeable backdrop walls for when we want to make a small indoor area. It would also be neat if we had more diverse hazard types such as fire, falling blocks, and rolling boulders. The monsters could be a bit more diverse too...
It would be nice if there was a way to save a specific item or model, so that way we could copy and paste items instead of having to hand construct each one, and maybe paste them in other levels.
 "Sandbox Hero"){kind=icon}
 "The Deepest Sleep"){kind=icon}
 "Mutilate-a-Doll 2"){kind=icon}