Seemingly anyone can have a hit with a free iPhone game, but how do you make money out of it?

Indie developers Danielle Cassley and Jason Citron might just be providing a blueprint for their peers, with the release this weekend of Aurora Feint II: The Arena.

It follows the enduring popularity of the first Aurora Feint game, a free iPhone title that offered a Puzzle Quest style mix of block-matching and character development.

What's interesting about Aurora Feint II is firstly that it's a premium title – £4.99 – aiming to capitalise on the huge audience that downloaded the freebie prequel.

But it's also interesting for the features it throws in to justify that price difference – specifically the asynchronous multiplayer element, where players upload ghosts of their best performances to duel against each other.

With chat, news feeds and player profiles around that. At a time when there's been something of a backlash against the thousands of bedroom-developed indie games on the App Store, Aurora Feint II shows the silver lining to that crowd.