Musical games dominate this edition of Mobile Monday, with two of our four features emphasizing rhythm and reflexes over any other gameplay mechanic. Also weighing in is the hefty game Zenonia, an RPG that claims a full 40 hours of 16-bit-style role playing!

Zenonia - One of the first full-length, original role playing games for the iPhone system, Zenonia packs a full 16-bit game into a tiny iTunes App. The action-RPG combines Zelda-like design with upgradeable skills and plenty of inventory management. The touch controls can be a bit fussy at times, especially if you're used to having a physical controller in your hands, and the dialogue is rough, but it's hard to argue with a full-length RPG that looks this retro-good.

World of Tunes - A too-cute rhythm game similar to the Nintendo DS title Elite Beat Agents. Tap each Tuney along with the beat as it flies to its target on the screen. You'll need to tap some Tuneys several times, while others need to be touched and dragged along a path. The music is good, if a bit sugar-coated, and four unique game modes give it plenty of replay value.

lilt line - Another stylish rhythm game, this one conjures images of old Atari-age racing titles with its vector-style visuals. Pilot a white line through passageways by tilting the iPhone left to climb upwards, right to move down. Every time the line runs across a white bar (which just so happens to coincide with beats in the music), tap the screen. Don't miss a tap and earn more points!

Platypus - That's right, the plasticine shooter is now on the iTunes App Store! The scaled-down port looks as good as its PC-based brother reviewed just a few weeks ago, and the touch controls are highly-customizable. A free Platypus Lite is also available.

NOTE: Games listed may not be available outside of North America. Prices are subject to change and are therefore unlisted. Please see the individual game pages for purchasing info.