It's a damn shame that the last third of this game played out like it did, because the first two thirds were absolutely magical for me. The world is teeming with life, and invites you to explore it without needing to resort to hiding weapons or upgrades anywhere. The second you step out of that cab at the start of the game into a snow-covered 1945 street, with Frank Sinatra christmas songs playing on the radio and people shuffling around under the moody street lamps, you know you're in for a treat. Atmosphere and immersion is central to the game, which makes it feel like the story takes place in a real living place rather than a cool digital sandbox.
You already know all about the linearity of the game, and how it's more of a linear game that takes place in an open world, rather than your typical side-mission-filled sandbox. Truth be told, the formula works fantastically for the 1940s section of the game, as well as the transition period between the 40s and 50s. The story stays interesting enough to push you forward as you get more and more involved with the mafia, and the missions vary and all serve a valid purpose rather than just being filler.
Unfortunately, the 1950s section of the game, despite featuring a couple of moments of pure brilliance, feels rushed. You meet gangsters and only do a single mission for them, you get thrust into a huge final confrontation way too fast without any real buildup, and the game ends on a painfully anticlimactic note. Actually, it doesn't even really end; it just stops.
Still, I guess you can't call it a bad thing that the game's only real shortfall is not giving us enough of it.
In a sentence:
Features many moments of sheer brilliance and what is probably the most realistic and living open world ever, backed by solid game mechanics and an engaging storyline. It just ends way too soon.