Ngmoco set iPhone on fire with its massively popular platformer Rolando, which made its sequel one of the most anticipated App Store games released so far.

And the developer seems to be very keen to grasp the new in-app purchasing and micro-transaction model now that Apple has allowed free apps and games to make use of it. The highly anticipated online shooter Eliminate has already been announced as going free, followed up with a fascinating new episodic take on Roland 2: Quest for the Golden Orchid.

The lite version has essentially been replaced by Chapter 1, which allows you to play the first level for free, then unlock additional chapters as an in-app purchase only once you reach them. Subsequent chapters appear to be set at the lowest pricing tier of £0.59 each.

This episodic approach to games is likely to become very popular (especially now devs can charge for them), and ultimately no bad thing for either the gamer or the developer. It'll hopefully encourage devs to make an extra effort to keep their games updated and exciting, while players will only be paying for a game as long as it maintains their interest and won't face any risks in trying them out.

Whether it works out better than charging a premium rate for the whole application or not, we'll just have to wait and see. There's no better test than Rolando 2.

Either way, the App Store and iPhone appears to be facing a provocative shift in its sales dynamic.

Want more? Check out our 11 other Rolando 2: The Quest for the Golden Orchid news stories!