Okay, my two cents:
New present-day "Half-Life" narrative implementation = well-done. However, I don't see how it could continue into AC5 (or whatever) if our silent protagonist becomes an Assassin.
I play this series purely for the story, and I found the concept of being a semi-rogue Abstergo employee absolutely delightful. Also,
Spoiler:I think that Juno will make a great villainess going forward, if they do it well. It's good to know that Rebecca and Shawn are still around. I find myself missing William, though.
I agree that the Frogger minigame is a pain in the kiester. For what it's worth, I found that I sucked much harder at it when I was tired. The two other hacking minigames were quite interesting, though.
So, in short, it works well here, but I hope Ubi switches it back to a named, talking present-day protagonist for the next installment.