Played this on Rift S. Performance is great even on my Geforce 1060. Gun mechanics were good. I much prefer this slow-and-tense pace in VR compared to faster games like Serious Sam 3 - I think because partially it's better for people with motion sickness, and the creeping around is more "real". As with Retriever I do wish there were a few easier targets to shoot at - the sentry guns are lethal and tough, which is good for tension, but a few soft targets would be nice too.
I'm looking forwards to the full release (if there will be one).