There's a few links to Altair in this game. He's mentioned a few times. I will say, collect the glyphs, and get the assassin seals.
The glyphs give you a BIG revelation into the story of the assassins. Kind of figured what it was when I got half way through, then when I got the final glyph and saw the full video, it was pretty freaking awesome.
The game got rid of the repetition though. All the missions are mixed up. Each mission is essential to moving on in the story. I'm probably a good 15-20 hours into the game, and just about at the end. Only thing I didn't collect is the feathers, but I think I'm gonna do that now before I move on to the end.
Also, the glyphs reveal A LOT of historical figures being involved, and I love how they mix them into the story and also a few historical events as well.
a little spoiler about the glyphs, just have a question, so if you haven't done at least 3/4 of them, you probably shouldn't read.