You're definitely limited to very old games. That doesn't mean they're not all bad though.
Check out the Half Life series, Portal series (Portal 2 is also an option, since I've played it on an even worse card before with okay-ish FPS). All in all, most of the source games could run well. Try out Gears of War too. You'll get good FPS at low settings and low resolution. Batman series are also options as they run on the Unreal engine, and they still look good at very low settings. You'll experience some lags at some points of the game though.