Steam itself has never limited things to running just one game. Games can make their own choices about whether to run with other things or not. For example, I think TF2 has some limitation on running multiple copies of it, but that's TF2's decision.
Nothing extracted yet.
hi, I can run all the games at the same time (with the lastest version-beta)
i remember in windows i can run only 1 game at once.
my setup : https://gist.github.com/stitchies/65ff11c266deae3222eb
Selinux is permanent off