Overall, not quite as good as "Then There Were None"...
For my liking there are too many times spent just waiting for other characters to finish what they are saying, and the puzzles are not always too challenging. Some are honestly ridiculous in their solution, which actually gets quite funny.
The game could have been made more balanced by allowing the character (you do not play Poirot, but a Train Company employee) to have more challenges and tasks. This is a shame, as the graphics are great, the sound (esp. voice acting) is wonderful and the interface is easy to use. Here's hoping that AC will continue to release more Agatha Christie games, and spend a little more time on the deveopmet of plot/story/puzzle.
Overall I would say that if this game retained the graphics, atmosphere and polish of this release, and combined it with the more user led system of the first release (Then There Were None), it would have scored in the high 8's or maybe even into the 9's.
Come on Adventure Company, you so almost have the formula right - how about another stab, say another Poirot (ABC Murders, Evil Under the Sun etc) or even a Jane Marple (4.50 From Paddington, A Murder is Announced, A Pocket Full of Rye, etc). The only question left - who would play the voice of Miss Marple now that Joan Hickson is no longer with us.