А они предоставляют исходный код?
вот на Crydev.net нашел
Code
CryENGINE 3 for Independent Studios, Free To Play Games or Downloadable Games
Crytek has attractive options for smaller games built with CryENGINE 3, with shorter development timescales.
If you want to move your game onto platforms other than PC, or you need access to CryENGINE 3 source code,
please contact Crytek to find out more about our licensing for Independent Studios.