Cogs is a 3D puzzle game that was originally released on iOS over a year ago, but it has just arrived on the Mac App Store. It's a good one, featuring a completely "mechanical" interface and sliding tile puzzles that build various contraptions of varying difficulty. The app is US$4.99 on the Mac App Store, but it's even cheaper on iOS; it's completely free on the iPhone right now, and it's $2.99 on the iPad as Cogs HD.
Unfortunately, even at those prices, the Mac App Store version is probably your best bet, as it comes with all 50+ levels unlocked and ready for play, while the iOS versions req
