I have to say, I'm a little more interested lately in longer and more developed experiences for the iOS devices, which is one reason why I loved Game Dev Story so much. But there is still some space in my app diet for quick, pick-up-and-play experiences, and Tap Disc is one of those. Actually, "pick-up-and-play" might not be the right phrase to use -- there is a lengthy tutorial with the game, and lots of things are happening. But at its core, Tap Disc is a pretty straightforward action game, and it's clean and satisfying enough to be well worth the buck it's selling for on the App Store right now.
The basic gameplay has you following a series of discs around the iPhone's screen, and you tap the screen to create matching orbs for them to touch. Touch to create an orb, then line it up so the bouncing disc touches it at the right time. The twist is that the discs are all different colors, and the orbs you create change colors over time. For example, a white disc simply has to hit a white orb, which is the color it is when it's first created. But a red disc can only hit an orb after it's turned red -- about a half second after you create it. You have to calculate the angles and time your orb placement just right in order to match colors and clear the discs.
It sounds complicated, but in practice, it's not. What you end up with is a fun mix of a timing and angle game that's pretty addictive. There is also a "preschool" mode for kids (much less complicated -- just tap the moving objects to clear them), and there are a number of different difficulties and powerups to contend with. OpenFeint integration extends replayability, and the team is even offering a monthly contest with cash prizes for the game's best players. Tap Disc is definitely worth checking out.