Hi,
Areas are very nicely detailed, just one thing for me they look a bit to 'plastic' but it's my taste. About the concept art i would say that the guy is very lucky with his drawings, they mix common sense with fantasy the right way. And for the trolls or other beast they can 'mingle?' with the countryside, lots of animals/beast have the power to do so and this can add a 'plus' in the game.