I have a few games on SteamVR that only show the theater mode option for
launching. I can launch most of my VR games fine from steam, but "Back
to Dinosaur Island"(for my kid) and "Ethan Carther" only show theater
mode as an option.
I grabbed it off humble store, so running it off steam. It's fantastic,
I crapped my pants the first time. I don't have a steering wheel, just
keyboard/xbox one controller. Just having a blast. I wish it had an
arcadey type kart mode, but still just ...