Altair's name in Arabic means "Flying one" or "Bird of Prey", his last name ibn La-Ahad means "Son of No-one".
Originally, the game included a crossbow for ranged attacks, but Ubisoft had this removed to make the game more challenging, as test gamers favored the ranged attacks over melee combat. It was also removed because it was historically incorrect. Although the crossbow is no longer in the game itself, an evidence of its existence is still in the trailer at the start up of the game - Altair is wearing it on his back along with a quiver of bolts.
As a joke, the game designers hid the image of Optimus Prime (Transformers) on certain buildings as an Easter Egg. The image appears as two boarded up windows above a triple shuttered window and can be spotted in more than one city on a number of buildings.
Altair is missing a finger on his left hand; unlike the rest of his order. Theories are that he had the finger removed to accommodate a blade of his own design.
At the beginning of the game, Altair is 26 years old, the same age as Desmond Miles.