Vastly improved sequel.
Super Scribblenauts is one of the few sequels I know of that fixed nearly every problem it's predecessor had and while some of the initial novelty of creating whatever you want to solve puzzles may have wore off, don't let that sway you from giving it a try.
This time around Maxwell has a new set of puzzles to solve with his magic notepad. One major improvement is more focused on puzzle based levels instead of platforming. The core element remains the same. You're given a situation and have to figure out how to solve it by creating nearly any item at your disposal. However this time adjectives can be used making a lot of solve way easier if you need a "big rock" or "fast car" or a "friendly pink dragon." This does make getting exactly what you need a lot easier though the game does throw in some adjective based puzzles where you need a very specific item to solve the puzzle. Though the vending machine/handcuff cheat from the first game has been eliminated, so don't expect any easy ways through the levels.
Also the major improvement most will tell you is the controls. I get why the first game stuck to stylus only control which was to be more accomodating to left handed people but now you have the choice of dpad or stylus. This is something all games should offer if touch and motion controls are going to be standard for the forseeable future. Different controls don't bother me but God knows some people love to whine if they have to do more than move their thumbs.
And finally when you beat a level, and beat it multiple times for the gold stars, the ollars you get now allow you to buy in game hints because as many know the first had some stages where the clues as to what to do were very vague and it definitely helps to unlock 2 more clues.
Other than the afformentioned improvements, not much else has changed though the game comes up with some fun level ideas including a Super Mario Bros. tribute stage and while not overly challenging the game does offer a sort of boss battle vs. Maxwell's evil doppleganger.
If you haven't jumped on the 3DS train yet and given great DS titles have gone down to a trickle now, it's still worth picking up now especially if you liked the first.