Today we're rolling out a game update for some players who were unable to launch the Oculus Rift version of the game, such as those who redeemed Call of the Starseed with their Vive content bundle. Affected players should see a 3GB update awaiting download.
To opt out of the update, or to remove the OVR runtime from your game files, simply right click Call of the Starseed in your game library, choose "properties", and then select "openvr_only" as your beta branch.
-Cloudhead Games