I finally got around to finishing this. The ending really did feel "gamey" and slapped together. The climb up the mountain really makes no sense (the other dudes apparently took the stairs, why doesn't she?) and the oni boss was a really lazy design. Look for the weak spot and shoot it! Too easy, let's make it during a snow storm so it's harder to see. Still too easy, let's throw in some trash enemies to annoy you. Still to easy, make them repeat it 3 times before the guy actually dies. The final QTE is lame too, I feel like it was just a set up to show her with dual pistols.
It's enjoyable gameplay-wise, but agree that the story kind of sucked. It was so disjointed from the gameplay and tried to hard to be dramatic. At one point there's a cutscene where Lara is all upset and says she has to go save someone quickly, but it deposits you in a new area so the first thing I did was wander around looking for collectibles. I also don't get why the devs were so obsessed with dramatic escape sequences. Like every 10 minutes she's jumping off burning buildings, collapsing cliffsides, exploding bridges, or whatever to get away from a few dudes that she could just turn around and slaughter.
Still, the core gameplay is pretty good. I think there's a lot of potential for the sequel to be awesome.