Let's be honest: there's no real reason for Scribblenauts Unlimited to be on the Wii U. It's not a graphical powerhouse. You don't need a TV screen to get the full effect of the game. For the most part, in style and substance, it's not that different from the previous iterations of the series that have appeared on the DS and on iOS devices. While there are certainly more "life situation puzzles" to be solved this time out (thanks for the description, Wikipedia!), there's nothing about it that screams, "This must be played on a console!"
To which I say: meh. Like all the other games in the series, Scribblenauts Unlimited is insanely fun, and the world is a better, happier, more creative place because it exists. I mean, where else do you get to shoot down a hornet's nest with a bazooka? Make your enemies pint-sized with a shrink ray? Pick a girl up on a date in a hovercraft? And better still, what other games give you the option of changing those scenarios entirely, and allowing you to pursue entirely different paths? None that I can think of, that's for sure.
On top of that, the game's new online sharing component has the potential to be something amazing. Now, in the interest of full disclosure, I'll admit that I've had major problems getting (and keeping) my Wii U online, so I haven't been able to explore this area as thoroughly as I would have liked. Still, you only have to look at the LittleBigPlanet communities to see that people like creating and sharing their gaming creations; if Scribblenauts Unlimited can come anywhere close to that level of community (and it doesn't seem like an unfair assumption to think that it could), then that should make an already fun game even more enjoyable.
And if it doesn't...well, as I said, you've still got yourself a fun game, with small improvements here and there that add up to make Scribblenauts Unlimited the best in the series. Case in point: the addition of a world map, which allows you to jump in and out of levels at random. Whereas previous games could start feeling like a bit of a slog as you pushed through seemingly impossible puzzles ("I have to add a what to the what now?"), here you can step back, take a breather and try another puzzle if one is proving to be impossible. Yes, you need to keep solving puzzles to earn "Starites" to unlock more levels to keep the game progressing, but by making lots of puzzles available all at once, the game has a greater sense of freedom and openness than before.