Problems with a game on the late 2012 iMac

I just bought a new iMac it's 3.2 Ghz Intel Core i5 8GB 1600 MHz DDR3 ram and NVIDIA GeForce GTX 675MX 1024 MB graphics Software is OS X 10.8.3 it's a 27" iMac. (My old 27" iMac did not have this problem it was a late 09 model) If I try to run the game Fallen Earth in high resolution on the toon select screen the arms and legs are gone if I start the game the same deal with all the toons in the game however everything else is fine and if i change the resolution to say 1600x1200 (4x3) the toons have limbs again but anything with resolution 1920x1440 (4x3) or higher and no limbs for the toons. I tried tec support and they said "best thing I can suggest in this case is to try updating your graphics card drivers to the latest version, and if they are already updated, try an earlier driver version which may be more stable with our Mac client". But I don't know how to do none of that Apple updates it's own drives right? And an earlier driver version? Is that even possible? Any suggestions, tips would be greatly appreciated.

 

Sorry about the text I did a copy and paste from my email. And I've contacted the devs but they have yet to solve the problem.

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That's great to hear thank you