FPS games are inherently a million times worse for VR sickness than room-scale walking around, since the former has the mismatch of the avatar walking around with the player sitting in a chair, while the latter is 1:1

HL2 is the only game that I felt nauseous from. Wonder why? I stopped playing though instead of trying finding a solution so I don't know if it's a known problem.

I actually got really naughtius playing half life 2 on the pc many years ago. Maybe there's something about that game.