A massive rollercoaster of a game that takes both climbs and falls in quality repeatedly. Overall though this game is too big for its own good and its best parts are found in the smaller less connected bits compared to the story at large. Since each part of this game is big enough to justify being its own smaller title I would rate each of them like so:
Part 1: 4.5/5
Part 2: 2/5
Part 3: 3/5
Part 4: 5/5
Part 5: 3/5