Branagh's approach to the subject was straight-forward. He established that Poirot is a man of deduction before launching into a murder mystery that engulfs most of the movie. His portrayal of Poirot was rigid and without flair. For a man who was theatrical, I have expected Poirot to be with theatrics as well. The main players of the mystery are deduced to pieces that are there to move the plot, with Poirot revealing more and more details about his passengers as the film progressed.
This was a slow burn kind of film, and if you're aware of the results, this might not be an impressive adaptation. I haven't read the book, but I have seen an adaptation of the piece; in terms of plot and progression, nothing is new for me. However, just because I was aware of the events does not mean that I cannot enjoy or be entertained by another adaptation.
This would have been far more enjoyable if one was to go in not knowing anything about it. The movie felt dry. I think it is possible for a well known work, even if it was adapted at numerous time, to wow people. Unfortunately, this wasn't it for me.