While Arno is far more versatile and skilled free-runner than previous protagonists, Unity overall is fairly boring and not very rewarding. The combat is fun and more challenging than previous iterations of Assassin's Creed games, but Unity's downfall is in the minor details.
What's the point of outfits if they offer no additional value? What's the point of doing all the Nostradamus puzzles? Why chase cockades purely for being able to colour your coat?
The map has so many icons that it's a little overwhelming. It's also annoying that a lot of the companion or Assassin missions are simply killing a specific target on the street. Bah. At some point, I just realized that all of the side missions are pointless and focussed exclusively on the main story. I'm done with less than 50% of the game overall, but I couldn't care less.