Nothing really good, nothing really bad, this game is just a huge scoop of meh.
This game is a lesser version of Assassin's Creed, there is a story, but it's not great, the driving and shooting/combat are not up to current standards. Some extremely frustrating parts in this game.
The side quests are better than anything that has ever been in AC though, I really liked diving into the history of Chicago told through the landmarks.
The music was ok, it's a shame most of it is hidden in unlockables throughout the world.
I didn't like the invasion stuff, it's easy to just ignore though.