Goat Simulator has open beta.
Make sure array is not empty
Cult of the Wind works.
Add Loren: The Amazon Princess

Tested on Gentoo Linux 64bit without the steam runtime, overlay works. Multi-monitor is poor with fullscreen split half on each monitor (one monitor's worth of resolution).
Merge pull request #170 from Tele42/patch-1

Add Loren: The Amazon Princess
Added Heroes Rise: The Prodigy & Heroes Rise: The Hero Project

Both don't have Fullscreen or Steam overlay, but not sure whether this
is a bug or if it is intended.

Also added this as a comment, linking to a relevant Steam discussion,
where I hope to get some answers.
Merge pull request #171 from ToostInc/heroes-rise

Added Heroes Rise: The Prodigy & Heroes Rise: The Hero Project
Mount & Blade Warband Linux beta
Merge pull request #172 from Tea23/patch-6

Mount & Blade Warband Linux beta
proper entry for Wargame: Red Dragon
Merge pull request #173 from Tea23/patch-7

proper entry for Wargame: Red Dragon
Fight The Dragon
Merge pull request #174 from psymin/patch-1

Fight The Dragon
Meltdown, Braveland, Foosball - Street Edition
Merge pull request #175 from psymin/patch-2

Meltdown, Braveland, Foosball - Street Edition
Space Farmers
Merge pull request #176 from her001/master

Space Farmers
The Last Door, Tabletop Simulator, Electronic Super Joy: Groove City, Spoiler Alert, Monsters Ate My Birthday Cake and Bridge Constructor Playground are working.
Merge pull request #177 from Daverball/master

The Last Door, Tabletop Simulator, Electronic Super Joy: Groove City, Spoiler Alert, Monsters Ate My Birthday Cake and Bridge Constructor Playground are working.
Drunken Robot Pornography works.