Greg Tito said:
But special mention has to be made of the original music composed by Stephen Anderson. I won't say it reminds me of an specific Assassin's Creed themes, but definitely creates an adventuresome atmosphere for Shalvis' antics.
Actually, it's funny that you should mention that. I was just thinking about that, and I re-watched the video specifically intending to try and pick out which parts were influenced by which Assassin's Creed soundtrack. Now, I might be mistaken, but I thought that I noticed that some AC themes are directly referenced by the music.
The very first part, immidiately following the initial attack, is from ACI, giving a subtle nod to both the Jerusalem and Acre themes; the same snippet is given a reprise of sorts later in the vid. After that, the ACIII Main theme kicks in, not a similar piece, but the actual theme rearranged for the video. That bit continues on for just about the whole vid, providing a base for the final nod: a very noticable part from ACII's main theme (called "Earth", it's pretty much Ezio's leitmotif), which appears the first time as a female vocal part way through the chase (much like how "Earth" starts), and reappears at the very end of the chase and over the credits, played on plucked strings (much like how it was at the end of "Earth").
I do agree with you, however, the combination of all the themes makes an absolutely awesome piece, and really captures the feeling of the series as a whole.
More on topic, while I think that the unnecessary flips were kind of dumb, they still looked pretty darn awesome.