A brilliant ability to create anything almost worthy of a 10 is hindered by horrible controls.
There's actually a story mode too. I estimate more than 200 levels are contained in it. In one of early levels you have to give santa something that he wants. A present, reigndeer, or many other things would give you the starite, which lets you win the level. Unfortunately some levels are extremely unfair or vague. For example in one of the later levels you are asked to "Find the imposter!" On the screen are three perfectly identical construction workers. I have tried interrogator, spy, and getting a gun and killing them all. I still have not figured it out. Levels like that decrease the fun, but there are many good levels too.
There is one thing that ruins the game, the controls. To move, you tap where you want to go. This is very imprecise and conflicts with many other controls. To move an object you spawn you drag it around with the stylus. This can make you move when you want to drag or vice versa. After you create many objects and set everything up the controls may kill you causing you to restart. If the movement was used with the D-Pad (or if you even had the option of doing so) I would give this game a 9 or 9.5.
Scribblenauts has it's ups and downs, but mostly ups. The game is overall pretty good. It has an amazing idea executed very well. But the controls and some levels bring it down. If you have a DS and some money buy or at least rent this game. It's worth it.