Little Big Planet, as the title implies, is both a simple little side-scrolling, platform-hopping, bauble-collecting adventure and a massively big game of game design at the same time. Bigness is never forced on you, however, and gameplay never exceeds your basic wants or skills.

However, behind the colorful cardboard cutouts, hints of advanced gaming are peeking out at you, invitingly.

The game's only characters, Sackboys (and girls) are best described as charming; little knitted critters with all the agility of a homemade puppet -- but pack a wardrobe that would make a hotel-heiress envious, which is how their winning personalities comes shining through.

Beyond the sackboys (and girls), there are no other characters. Everything else is built from objects and materials found in the world. Like a middle-school play, castles are made from painted wood and decorated with stickers, the king from cardboard cutouts. It's pretty surreal, Terry Gilliam-bizarre, and entirely engaging because of it.

As a single player experience, the lengthy story mode is entertaining and challenging. As you start and then progress through the story, basic game mechanics are introduced; instructions become less obvious as the difficulty ramps up while the control scheme never extends beyond no-brainer button-and-Dpad input. Pretty cool old school; deceptively simple, increasingly stimulating... with some new-generation high-definition pizzazz just to remind you of what school you're actually playing in.

If you're willing to take a leap into the world of level design, a handy tutorial walks you through the basics of creating your own little side-scrolling, platform-hopping, bauble-collecting adventure. From there, if you care, and if you're the imaginative sort, this level creation bit goes deep -- really deep, sky-isn't-even-the-limit deep. (Many users, for example, have broken from form and skipped on the platform-hopping, bauble-collecting remakes and created straight-up racing games out of the tools at hand).

Be warned: Trying to sculpt a complete world is a long difficult process. Even trying to build a little snack-sized, single-serving level that others will enjoy is a challenge, but a thoroughly rewarding one, much like Mechano or Tinker Toys, except that it nets you a product of playful permanence, something that can be shared online with millions of others.

In fact, through the process of building and testing, testing and building, you'll gain a new appreciation for game and level designers in general.

Hopefully, as the online level-sharing community continues to work on custom Planets and one-off Little Big segments, Little Big Planet will evolve into a game much larger than the sum of its parts. As it stands, you can choose which parts to play, free, making it a game that never gets old and doesn't charge you money for fresh new content or "expansions." As it stands, there's currently an overabundance of Little Big toy car races and bauble-collecting challenges, but that's not necessarily a bad thing; just indicative of a new model for social-interaction in its infancy.

Fortunately, there's a vote system whereby users hop online and test the Planet's user-created offerings. Giving each a shot is an exciting mixture of surprise and dread. In some cases, a simple racing game can add a new level of competitiveness between friends; others might see that said same game as a boring ride on the backs of toy cats. But just play it, rate it, tag it and move on. The people's choices rise to the top. And when you do find something you like, you can sort available content to show more games like it, or more by the same designer.

When speaking of Little Big Planet, there is perhaps not a phrase as appropriate as "you get out of it what you put into it." As a single player, story-based experience, the game is enjoyable enough to be easily recommended. But factor the level-creator tools and plethora of user-generated content into the mix and Little Big Planet is surely a must-play -- must own -- game.