The GMA950 is by no means a bad chip and can play new releases, albeit on low settings. However, for this, it is essential you have 2gb of ram, even 1gb is a little too small.
However, don't bother with gaming on OS X. Not only does Apple limit the GMA950 to 64mb of ram on OS X, which I am fairly sure is unchangable (rendering it near useless), but the 950 is slow with OpenGl, and most Mac games are ports, and so slower than the original.
The result being a vast slash in game performance on OS X.
Just "get" a copy of Windows XP, download bootcamp, and use Windows to play your games. Not only will you multiply the number of games available to you by a few quadrillion, but they'll run much much faster. Windows allows the GMA950 up to 225mb of RAM, increasing performance immensely.