Wonderful, fun, different, beautiful
The puzzles were interesting but not overly hard to cause frustration. I personally liked the ramp up in difficulty of puzzles and combat instead of some ten minute tut and throwing you into. The combat reminded me much of the original TR games where combat wasn't the main focus but exploring and interacting with the environment was.
The only negative I saw was it wasn't longer than it was. I got 12hours on my first run through. Still I had not found a third of the secrets or got near all the achievements when I finished. I have played the game three times since buying it and just started on the Survivor levels which are a wonderful twist on GEARS's horde mode imo.