Summary: Challenging, but not frustrating to play. At the end of the game, maybe 4-5 hours total, I was disappointed that that's all there was. I kept expecting a seriously hard level, and except for one of the bonus challenges, most puzzles/challenges were pretty simple to solve. (for me at least) Only one person can save game/score at a time meaning it cannot be shared among a family like Brain Age or Mario Cart. That's a big disappointment.
Summary: Most of the other reviews cover the gameplay well. It's simple to understand the controls, the puzzles are fun, and there's a scoring system to help encourage you to not waste time. :) But, only one review mentioned what is IMHO the biggest flaw, something that IMHO is unconscionable on any game system, even the DS: the game will save only a single player's game! That's right. Sharing the game and/or DS with your family?
Summary: I got this game as a Christmas gift for my 13 year old grandson who likes putting things together. It looks like something he would love to play. Can't rate it honestly until he plays it, but I hope he will enjoy it. He loves his Nintendo DSI.