Plus you can retry a puzzle as many times as you wish, and even skip it. And for those who really love a challenge, each puzzle can be replayed on a more challenging level, which requires more goo balls to make it through to the exit.
Not only are the puzzles fascinating to explore, but these goo balls have personalities. When touched, they reveal eyes and emit cute gibberish sounds, making them adorable and endearing.
Adding to this game's appeal are striking Dr. Seuss-like visuals and a riveting musical score that varies to enhance each puzzle setting. You'll hear soothing string orchestrations in calm environments and discordant sounds when goo-popping spikes are near.
While young children will initially be able to play (and in the process learn a thing or two about physics), this is a game best played by tweens, teens, and adults who won't get stymied when the puzzles get harder. Plus, the wry humor will be lost on little kids.
A boxed Win/Mac computer version is available at retail or via download at www.playwithgoo.com. The Linux version can be downloaded at www.2Dboy.com. The Wii version is available as a download, and it offers a unique cooperative mode, which can be fun for families.
World of Goo is a tour de force. Its puzzles are simple in concept and pleasingly difficult to solve. With its stark graphics, endearing living building materials, captivating music, and a quirky sense of humor, this is a game worth playing. Start with the free demo and see if you too get hooked.
RATING: 5 stars (out of 5) Best for ages 10-up From 2D Boy/Brighter Minds Media, LLC, www.playwithgoo.com, $20 (Win/Mac/Linux), $15 (Wiiware).
Jinny Gudmundsen is the kid-tech columnist for USA Today.com and Gannett News Service, and is also the editor of Computing with Kids (www.ComputingWithKids.com ).