GemStone Challenge credits :

- Design, Graphics and programming by Julien Wyart

- Powered by cocos2d Application framework for iphone (www.cocos2d-iphone.org)

- Music : Arcade Music Loop by MartynHarvey, Starian by MusicShake (bought on www.audiomicro.com)

- Jungle Fever Font from www.1001freefonts.com

- Graphic Textures from the Genetica Texture Packs (www.spiralgraphics.biz)

- Thanks to my wife Gwenaël 

- Thanks to ray wenderlich (www.raywenderlich.com) for his helpful tutorials