The game is an ideal timewaster -- my favorite kind of game -- perfect for waiting in line or on the subway.
Frenzic starts off easy enough: you're presented with a colored pie slice, and you must move it from the center of the game board to one of six other pies. Simply complete each pie with six pieces of any color, though matching colors wins extra points and bonuses. A video showing how the game is played is available here.
As you progress, the time you have available to park the current pie slice decreases. Gameplay gets challenging when you are given a piece for a position you already have six of: then you lose a life.
Daring Fireball's John Gruber noted yesterday (and I agree) that gameplay is ideally suited to the touch interface. He said that while the desktop version required precise mousing, the mobile version is perfect for finger-based gameplay.
Additionally, the sound design is excellent, with a scheme that matches the visual design very well. Even buttons that look like normal iPhone buttons have sounds associated with them, which is a nice touch. That said, the game is extremely playable without headphones, too.
Frenzic is well worth the $4.99, and is available in the App Store. The desktop version of Frenzic is also available starting at $10. ($15 buys you access to online features like statistics and friend tracking for life.)
Also, if you're interested, Frenzic developer Craig Hockenberry has some tips related to his experience launching Frenzic about how to time your worldwide launch. He links to some awesome screenshots of prototype designs, too.