If you or your girlfriend aren’t prone to motion sickness, I’d recommend the Portal games and Outer Wilds.

All games from Supergiant games are an automatic recommend from me, but if you’re not into fast paced violent games which a spectator might not be able to keep up with, maybe skip Hades and go for their earlier titles.

Both Ori games may be a good choice too since she can enjoy the eye candy and story alongside.