US developer EpicTilt has launched another artist-focused iPhone music game, this time for rapper Asher Roth.

Called Do Something Crazy!, it's available on the App Store in a free Lite version, with a premium edition to come. It includes a spot-the-difference game, a photo-editing section to put Asher and various "frat-party items" into users' own photos, and Roth's latest video.

Launched through a licensing deal with Roth's label, Universal Motown, the game follows EpicTilt's previous titles for Lady Gaga, Akon, Lil Wayne and the Pussycat Dolls, as well as two games for ESPN.

Although these games are very different in style and content to Tapulous's Tap Tap Revenge spin-offs for bands like Coldplay, Weezer and Nine Inch Nails, the two companies are shaping up as rivals.

That will only increase when EpicTilt releases its first standalone music game, TapStar, in the next month.

EpicTilt is describing it as "the first music game with loads of content from superstar artists", and says players will be able to "download levels from your favorite artists and show off your TapStar skills to your friends".

In the continued absence of console music franchises like Guitar Hero and Rock Band from iPhone, companies like Tapulous and EpicTilt are building their reputations and their relationships with the record labels.