or you try this engine, we have change to NA engine for 2 weeks ago. its fantastic and very easy to use for an designer, but you need good c# skills for gamelogic and more.

http://www.neoaxisgroup.com

here pictures of our prototype demo createt in NA engine
http://www.neoaxisgroup.com/phpBB2/viewtopic.php?t=2026

cheers
Christian_Ger