Even with Tegra 4 the games are way too slow (don't expect any playable frame rates on the Ouya!), i can just about play nights on my nvidia shield to some degree, but until the next gen of mobile cpus come out this isn't worth bothering with atm.
There is another build floating around that's quicker than the play store one, i think thats the one i was using but again, none of them are at a state of getting any enjoyment out of them.