As the title indicates, Feral (linux game port developers), now recommends the padoka stable ppa when needed in the official steam game requirements page. its always nice to have ones work recognized.

stable padoka: https://launchpad.net/~paulo-miguel-dias/+archive/ubuntu/pkppa

unstable (git) padoka: https://launchpad.net/~paulo-miguel-dias/+archive/ubuntu/mesa

enjoy!