Considering how many people use their iPhone as their primary portable music player, it?s surprising to see how few rhythm games there are.Sure big titles like Tap Tap Revenge has taken off like wildfire. But competitors to the handful of successes you?ll find are few and far between.That?s why it was such a delight to stumble across World of Tunes, a colorful adventure filled with great music and charming visuals.

An evil villain has stolen all of the music from the World of Tunes, and it?s up to you and the population of Tuneys to vanquish the villains and get it back.

The gameplay in World of Tunes may seem familiar to anyone who?s played Elite Beat Agents on the Nintendo DS.The core mechanics of the two games are incredibly similar, if not identical.Tuneys, the little blue fellas that make up the World of Tunes residency, will pop up from the bottom of the screen inside of an ever-shrinking circle.When that circle gets close enough to electrify the Tuneys, you tap them with your finger.This is all done to the beat of the music.The goal of the game is to keep the meter at the top of the screen from running empty before the song ends.Every time you miss a Tuney it?ll drop again.

There are a few other tweaks to the regular gameplay that keep things interesting like chaining together huge combos to refill your meter, large Tuneys that take several taps to clear, and Tuneys that you need to drag across musical paths.All in all, there?s a lot to the gameplay to keep things fresh.

The music is all original, top notch, and stays fresh from track to track offering up completely different experiences due to the changing tempos.

The only real complaint one can make about World of Tunes is how short it is.The entire game is comprised of only 10 levels; 6 regular and 4 boss battles. Each of these can be completed in 2-5 minutes.Overall we?re talking a 30 minute experience, tops.And while the boss battles offer up some cool variety and challenge (think regular levels, but with special tricks to clear the baddies), getting to tackle one every 5 minutes just doesn?t make them feel all that special.

There are a few technical choices as well that, while in no way obstructive to the gameplay, seem indicative of the developers desire to rush this one out the door.The iPhone?s status bar which displays things like a clock and battery life indicator is almost always written out of the code for a game, but in World of Tunes it?s been left completely in tact.The cinematics, too, show technical signs of being rushed.Rather than being written into the program whole-heartedly, they?re shown through the iPhone?s video player.If you tap the screen during playback the standard video options overlay pops up over the game.Like I said — nothing that takes away from the gameplay, but both things that can take you out of the experience.

A few other modes are available outside of the standard game, but rather than introduce new challenges or music they simply add some gameplay modifiers that adjust the difficulty.DJ mode, for example, keeps the Tuneys popping up in straight lines to make the game easier.Crazy mode, on the other hand, has the Tuneys moving in an unpredictable fashion.While it?s nice to see anything get added to this otherwise thin package, there?s just nothing in the bonus content that screams ?more reasons to keep coming back!?

World of Tunes is a perfect rhythm game for the iPhone, but it?s over just as soon as it starts.If they were to snowball the success of this title into a full-fledged game with a greater number of stages it would earn our whole-hearted endorsement.But as it stands, even the low $1.99 price tag is a little steep for what you?re getting.