Well, it let's you play some games. Sometimes the games can be software rendered but that's quite slow. The GPU lets you accelerate that (like your video card) and allows you to play other games that do require it.
It's quite old though, the GPU. Don't expect to play the latest games, but hey it's something!
Angry Birds does run. It's super slow though We did some benchmarks against the Rhodium guys and we're pulling in just about the same FPS, so if they can play it chances are we can too.