The release of id's on-rail shooter RAGE has generated plenty of discussion among gamers, but it's also providing some interest for App Store analysis.

Released in two forms - a 99c universal app and a $1.99 HD app specifically for iPad and iPhone 4's high graphical capabilities - both games are quickly climbing the charts.

However, what's interesting is it's the $1.99 version that's currently strongly outselling the 99c, despite its smaller potential install base.

HD quality

At the time of writing RAGE HD was #11 in the US iPhone paid chart (#5 in the iPad chart), while RAGE was only at #61 in the iPhone paid chart.

This demonstrates that for a high profile game from a studio such as id, the vast majority of early adopters are prepared to pay more for a higher quality experience.

It will certainly be fascinating to see how the sales between the two versions play out over time.