This app was mentioned in 2 comments, with an average of 1.50 upvotes
I’m curious what games you found that are no longer on the Play Store.
Here’s some apps I’ve tried and liked:
Wrong Level and Wrong Voyage. Two short exploration / puzzle apps. Great atmosphere.
QVR and DVR are engine ports of Quake and Doom. As with all ports, be careful on motion sickness, quit as soon as you start feeling funny.
Xash3D VR is an implementation of the Half Life 1 engine. Controller setup is tricky as the game was definitely not designed for anything but keyboard and mouse, the UI is hard to see out in the periphery, but it’s my favorite by a mile. Has a cool story and a lot of content. Needs the original Half Life 1 files (NOT HL Source!), but you can get those on sale very frequently (probably for Valentines it’ll be $1 again).
Flats is a simple online FPS.
Haven’t tried these, but they look promising:
new version based on Google Cardboard SDK
https://play.google.com/store/apps/details?id=com.Fguillotine.WrongLevelVRCardboard