I'm going to attempt to keep this more up to date but seeing as games have been announced for Game Pass, I figured this would be a good time to get this going.
Additions (September 1st)
Aven Colony
Giana Sisters: Twisted Dreams - Director's Cut
Halo: Master Chief Collection
InnerSpace
Manual Samuel
ONRUSH
Quantum Break
Shadow Warrior
Sky Force Reloaded
Snake Pass
Removals (August 31st)
10 Second Ninja X
Pro Evolution Soccer 2018
The Bridge
Galaga Legions DX
Pac-Man Museum
Soul Caliber II HD Online
Tekken Tag Tournament 2
Additions (September 1st)
Aven Colony
Giana Sisters: Twisted Dreams - Director's Cut
Halo: Master Chief Collection
InnerSpace
Manual Samuel
ONRUSH
Quantum Break
Shadow Warrior
Sky Force Reloaded
Snake Pass
Removals (August 31st)
10 Second Ninja X
Pro Evolution Soccer 2018
The Bridge
Galaga Legions DX
Pac-Man Museum
Soul Caliber II HD Online
Tekken Tag Tournament 2