I usually don't review games like this, buuut I think I should.
I want to first say that it wasn't a let down, but I don't completely recommend it. If you enjoyed the other Scribblenauts games, there's a chance you won't really enjoy this one. Instead of the last games, there's not unique places and certain quests to do. The quests in this game are repeatative and you have to do the same ones over and over again despite what location you go to. For instance, someone tells you to bring 3 people their donuts; you find this task numerous times in gameplay. There are many others that you'll find yourself getting deja vu.
The controls and mechanics are still the same for the most part. The only difference is that you can't use the same word twice in one location gameplay or you'll be tallied -50 points. You also can't create your own avatar either, you're stuck using the vanilla Maxwell character. Another thing is there's much more talking in this game; yet there's still little character development. A few cameos of the last game were mentioned.
However, if you're a DC fan, you might enjoy it. I'm personally a Marval fan so I wasn't too fimilar with much besides Batman. Although there are mostly all of the DC characters you can imagine; even original ones from generations ago. You can visit their unique locations and do their missions and experience their past life in a quest.
So in general, Scribblenauts fans be careful of buying it because it's not what you're expecting. If you're just looking for some entertainment, DC and easy achievements, go ahead and grab it. I'd wait for it to go back on sale though.