Though created primarily to "spark teens' interest in mechanical engineering," TinkerBox offers machine-building fun for all ages.
The game (simulator?) starts with a dozen training levels, which teach you to place, use, and tweak the various tools at your disposal: buttons, conveyor belts, levers, and so on. Of course, different puzzles have different tools available; it's your job to figure out where they go, how they interconnect, and so on.
Basically, if you've ever played The Incredible Machine, you'll find yourself in familiar territory here. TinkerBox looks dazzling, and it's a blast to, well, tinker with.
Alas, it has just two levels--"The Lab" and "Steel Mill"--with a combined total of just 13 puzzles. Two additional levels are marked "Coming Soon," but for now the game is woefully short.
On the other hand, it's free, and it does come with a slick builder for creating your own inventions (which you can then e-mail to friends). Plus, if you point your iPad's browser to Autodesk's Tinkerbox site, you can download inventions shared by other users.
I really like Tinkerbox. I just wish the puzzle-solving part wasn't over so quickly. (Guess it's back to Crazy Machines for iPhone/iPod, which is long overdue for an iPad version!).