Why is PC the only platform listed, and not Oculus and Vive? As far as I'm aware, there's no non-VR version of this game.

the game is played on a PC, so we call it the PC version.

I'm playing the game on an Oculus Rift, why can't I select the Oculus platform like every other VR game on this site?

just select PC. Rift, Vive, and Index are all played on PC.

So far I've only played this game casually and I came here because I was considering speedrunning it. What I'm saying is that Oculus/Vive should be added because they're platform options and this would make it consistent with other VR games on this site.

I think you're not right. I played on HTC Vive and it's exact difficulty(to speedrun) as Index Valve.(speedrun with spin) But maybe i'm wrong cause i never played on index or oculus so who knows?

He's not saying it's any easier or harder on another platform, he just wants the option of selecting Oculus as a platform because it's one of the two SRC actually provides and most other VR games on the site let you do that.

Hmm. Maybe it would be great idea.