Yes, you can see examples of games done with kivy in the two contests (kivy.org/#contest), and there are also a few games on the market, it's also interesting to look at kovak's efforts on kivent.org, a 2D game engine built on top of kivy and cymunk, which seems like the way to go for games with a lot of actors.
There has been at least one user working on it, for kivy, so maybe it'll available soon, either as 3rd party package, or as a PR to either project (though it would probably make more sense on kivent).
