Mac Mini Early 2009 Graphics

I'm using a Mac mini Early 2009, and I looked at my Graphics for it and it's running a NVIDIA GeForce 9400 256 MB. most games I know of need a MUCH higher Graphics Card. Correct me if I am wrong, I don't know much (if not anything) about Graphics Cards and Drivers, etc. Is there a way to upgrade my Mac mini's graphics (card)?

Thanks!

Mac mini (Early 2009)

Processor 2 GHz Intel Core 2 Duo

Memory 8 GB 1067 MHz DDR3

Graphics NVIDIA GeForce 9400 256 MB