Were you ever playing a game when you thought 'I could do this much better if I had a certain object'? Like wanting to cleave through a horde of zombies with a lightsaber or race past all those fast cars ahead of you on a neon, rocket-powered goat? Scribblenauts Unlimited is a game where you can do just that. Your only weapon is your knowledge and imagination. That and the stuff that materializes once you write it in your notebook. Right, so in this game you have a magic notebook that can create anything that you write in it. No it is not your pen that is magical, it is the notebook. The game is very explicit about that.
The game is a 2D-scroller and can also be considered an open-world. You are zlorped (that's the sound it makes) to a level and that is where you do stuff. 'Do stuff' is about as specific you can get in this game. The 'stuff' you have to 'do' varies greatly. I gave a chef a spatula so he could use it like a pogo stick to sled down a hill. It was very disturbing to watch. I recommend you not making the same mistake. You are placed in several scenarios and need to overcome them using your wit. There is no obligation to rush. You can take your time, roam the world and experiment with different scenarios. Your ultimate objective in the game is to collect 'starites' which are born of the happiness of others. So what you do is help people and poof, you get a starite or starite shard. When you get enough starites you finish the game, although that is no reason to stop playing. You only stop playing once your curiosity has been satiated. But as long as you have questions like "What would happen if I fed a starving chicken an omelet?", you will not stop playing.
There is a new feature to the game that none of the previous versions had called the 'Object Editor'. Here you can create your own objects using things that already exist as a frame. For example I created Greymon (Digimon) using a T-Rex as a frame. I also created Agent 47 (Hitman) using a guy in a suit. You can also create your own avatar, which is what you walk around as in the game. That is what I did with Agent 47. With Steam, you can share your custom objects online and expand your Scribblenauts vocabulary. If you have Wii U, then you will have bonus content, which is characters from the Mario universe and the Zelda universe.
The background music for Scribblenauts Unlimited is good, the kind of stuff you don't notice straight away but if it weren't for the music you would not enjoy the game as much. The music doesn't overdo it, it doesn't draw away the attention from the game. The game's cartoonish visuals are complimented by the music the same way as Yoshi's Island.
The range of animation for each and everything is limited, and a little variation would be much appreciated. I don't mind it being limited and by limited I mean for every melee attack you flail your arms wildly. Whether you have a sword or a brass knuckle that is all you, or anyone, will do.
The storytelling is a limited element in this game, which is much more than could be asked of Super Scribblenauts. The storytelling is just beautiful in this game. The narrator's voice, which is very nice and present only for the start and end movies, is reminiscent of the interactive children's shows like Blue's Clues. The only difference is that the narrator isn't condescending; she will not ask you if you see a hole in the boat while pointing to a boat missing half its deck, like in Dora the Explorer. The story in itself is just 'sweet'. It is not a vital part of the game, nor was it meant to be, you can play this game without knowing the story and it will not affect your gameplay experience one bit.
Scribblenauts Unlimited is not very challenging. The game might have been intended for a younger demographic, which might explain the low difficulty. If you take too long to solve some of the challenges, they get even easier, which is annoying. Compared to Super Scribblenauts, this is a downside. The first level in Super Scribblenauts was hard, most of the levels were. For the first level you had to name four different creatures with a long neck. Snakes don't count. Try it.
Another shortcoming is that checking for ways to get additional shards is a hassle. You have to open the pause menu, click on 'Shards', choose which type of puzzles you want to solve, get to the page with unsolved puzzles and then you can get to solving it. But if you forget the puzzle then you have to repeat those steps all over again. Doing things in the heat of the moment is a bit difficult. There is no specific button to attack someone, enter a vehicle, throw something or perform any one of the context sensitive actions. To do something you have to click on the person, object or vehicle in question and choose the action. For people who play RPGs which require intensive use of the mouse, this might not be a problem.

Verdict: This is the sort of game you spend more time on then you mean to, or need to. Looks and sounds go well together, gameplay is unique and fun.