>>382812445
After The Fall is a fun coop zombie shooter.
Hyper Dash, Contractors, and Onward are all crossplay shooters, but they're more PvP focused. Contractors and Onward do have some barebones coop stuff though.
Ragnarock and Beat Saber both support crossplay, but not with custom songs.
Eleven has crossplay if you wanna play table tennis.
Zenith is worth considering if you like MMOs, but most people think it's kinda disappointing in it's current state. I think it's still fun enough when you're playing with friends though.
I'd second VRChat too if you just want to hang out together in VR.