I've been playing games since 1983 and this is one of the best ever.
Game has a great authentic atmosphere that sucks you in to the game and to WWI. sound track is amazing and the story can fit a true historical/adventure/romance novel. Graphics are superb and the true historical notes puts you right in the middle of the battle. The only bad thing I can think of is that the puzzles aren't so hard but just right in order to get the game going and not get you stuck somewhere for hours (days) figuring out what to do next.
I really loved this game and hope others will take this as an example and make more (WWII???)