Adventure fans could be in for an early Christmas treat with the announcement of Mystery of the Crystal Portal 2: Beyond the Horizon from G5 Entertainment.

It's been several years since the release of the original mystery, which was widely successful on a variety of platforms.

Mystery of the Crystal Portal 2 will continue the story of protagonist Nicolle Rankwist, a journalist following in her father's footsteps to find an artefact with the power to change the world.

Set for release on 2nd December, the sequel will also feature Game Center achievements, multitasking, and support for iPhone 4 Retina display - G5 promises that the HD version will look 'especially crisp'.

Not content with the announcement of a new title, G5 Entertainment has also promised a week of discounts on the App Store, with one iPhone and iPad game being reduced to 99c every day from 22nd-28th November.

For more information on the promotion, visit G5's App Store page.