Nice add-on for the franchise.
DS version is a prequel that takes place just before the actual game released in 2007. There is a mysterious Chalice somewhere in the Holy Land and whoever possesses it can turn the tide of the third crusade to favor whatever faction he or she wishes. A young assassin named Altaïr goes on a quest to retrieve this Chalice, but as time progresses there are a lot of twists and turns to be made. DS game's conclusion is very unsatisfying, but it ends just where the console game begins.
Graphics are nice. Environments are big and the animation of characters is smooth and well done. There are a few cutscenes and their graphical presentation is even better, but they are too few and far between. The use of bright colors ensures that you'll always know what you're looking at despite of the DS's small screens. All the action happen mostly on one screen only, but at times there is some use of both screens.
Perhaps because of the limitations of DS cartridge there are only a few musical tracks available and this causes some serious repetitiveness: especially that aggressive theme during combat gets old really fast. Other sound effects are mostly there just to create a mood of living city with lots of sounds. At the same time the actual sound of Altaïr's movement is almost non-existent and there is no real voice acting what so ever. In short the sound design in DS's Assassin's Creed is passable, but by no means great.
Gameplay is a linear third person platforming with a little combat and fixed camera angles. Social stealth that made the console game so great is kept to a minimum. There are 13 chapters as a whole and it takes around 6 to 8 hours to breeze through. Gameplay gets quite repetitive after a while so it's advisable to play it in small doses. Camera is handled well most of the time, but still it causes irritating sudden deaths every now and then. Nothing you can't get over with because of the frequent checkpoints of the game. Combat is slow and although you get combos and new weapons as you go you can play through almost the whole game from start to finish by just tapping that Y button over and over again in combat. Touch screen is used in a few pickpocket and interrogation minigames: it works well.
Assassin's Creed: Altaïr's Chronicles features a prequel story and some great platforming. It also includes irritating camera, repetitive gameplay and music topping it all with a clunky combat system. Game is worth playing, but not nearly as good as Ninja Gaiden Dragon Sword for example.