At CES 2019, HTC was showing off a Battle Royale FPS named Population: One by developer Big Box VR. It offers a lot of the same features found in Fortnite and PUBG, but in a wild VR sandbox. I got some hands-on time with it, which is still in beta, and overall I had a blast.
Population: One can be played in both single-player against bots, or multiplayer in teams on either HTC Vive, Oculus Rift, or Windows Mixed Reality. The essential design of the game is similar to Fortnite in that you have to eliminate the other teams’ players using a variety of weaponry, and as the game goes on the safe area continually shrinks until there’s a winner. The Fortnite connection really comes through in the game’s building mechanic, which lets you erect walls pretty much anywhere, which you can then climb, run across, or hide behind for cover.
Source: IGN.com Population: One Isn't Quite 'Fortnite VR' But It's Pretty Convincing