Sega's classic ChuChu Rocket! puzzle title is on the App Store for both iPhone and iPad right now. I've been waiting for this one for a while. I loved the old Dreamcast version, and the remake for the iPhone not only recreates the mouse-redirecting gameplay (you place arrows on a board to guide mice around cats and into their mouseholes), but it adds a few iOS-specific features as well. There are 145 puzzles to play through, and as a special treat, Sega has added a one to four player multiplayer capability via Apple's Game Center; there are achievements to score as well.
The iPhone version is US$4.99, which is less than you'd pay if you found the used Dreamcast version in a store somewhere. The iPad version is $6.99, but it includes a multiplayer mode where up to four players can play on one screen -- it sounds pretty crazy. This one is a classic puzzler that you should definitely check out even if you never played the old game. We're lucky to have it up and running on iOS.