We for sure got a very good or a great product here. I doubt the game won't stay at the same quality as I advance through it.
I'm talking about a good FPS that can be call a survival game with good graphics, good sound, and very good stuff such as own death animation. The riddle or puzzle are cool and fun to solve and the gunning aspect of the game so far make a lot of sense. All this with a pretty cool story that start with a very nice demo to prove this game is solid. And of course, a solid background with the series history.
The only problem for me and so maybe the pro or the elite: The slow running speed.
So if you got strong nerve and search for a good game this time of the year and interested after the demo, jump on it. Can't miss that.