I really really enjoyed the climbing mechanic but I couldn't pass the part with the flares since I couldn't see anything and I got frustrated trying to climb in pure black. Also there was some weird flashing light in the elevator, which kinda hurt my eyes.
With better lighting, however, I think this could be a really spooky and fun game. When the light went out, I audibly went "ah shit, no..." because I was NOT looking forwards to finding whatever horrible things lived in the cave XD So a good horror bit right there.
And the climlbing mechanic, once again, was very fun, I really enjoyed getting into the zone and just going. I want more but like... With a flashlight XD