GAMING IS BUILT ON the idea that imitation is the most sincere form of flattery. Almost everything in videogames is lifted from a previous work; in the best cases, old tropes are blended to form something better than the sum of their parts, but in most, it results in games that can be described as "like X, but with Y, too." (Example: every rhythm game you've ever played.)
And then there are the rare games that try something completely new. Most fail, having overstepped the abilities of their designers or the boundaries of their clever new idea. (Example: Braid, a phenomenal game that almost no one played.)
Then there are games like Scribblenauts. It's built on an ingenious idea, it's immediately accessible and, bafflingly, there's nothing out there remotely like it. You play the role of a boy tasked with solving many, many puzzles using only the power of your imagination. When presented with a goal, you simply type a word into the game and whatever you thought of instantly manifests inside the game world for your usage. Would a dinosaur somehow help you snag that far-away star? Summon a tyrannosaur and enjoy your new pet. Need something shot? Type "gun" and ventilate the world around you. With tens of thousands of words available for your summoning pleasure, you'd have to try hard to run out of things to do in-game.
If the game has one flaw, it's that constant use of the stylus to type and move can be vaguely annoying—but compared to all the goodness packed into Scribblenauts, it's a very weak argument against. Scribblenauts is not only full of clever gameplay options and an adorable, addictive art style, it represents the most inventive idea in gaming since the original Super Mario Bros. It's the proverbial "important" game, and everyone with a DS should buy a copy. It's a nice coincidence that it's also the most fun you'll have on a handheld system this year.