User blog comment:Reversinator/Trailer for Scribblenauts Unlimited/@comment-4637670-20120605211104/@comment-1622817-20120606010010

We don't really know how creating objects work, so while I doubt it's playground only, there's probably a limit of sorts put in place. Besides, it's going to challenge people's imaginations more because it allows for the creation of very cool-looking things.