The graphics are great, considering what can be done with the PSP's capability. It's too bad Altair's voice is not the same as in Assassin's Creed, and sounded more of an Arabic voice, but you get used to it.
The storyline can keep you going for 5-10 hours, which is a shame, since I have an Assassin's Creed game on my iPod Touch that lasts just as long. You still have the same weapons as in AC1, but it seemed a bit easier to kill soldiers with the hidden blade and countering. There is an ability to upgrade, which is a nice feature, and there are goals in the game, like "Kill 100 men by countering", which gives you a feel of accomplishment. More weapons can be unlocked by connecting the PSP with the PS3, which is good for PS3 holders of Assassin's Creed 2.
Meanwhile, subtitles have spelling mistakes, and the voices are sometimes delayed, which gives people the feeling that there wasn't alot of effort put into creating the game. However, one cool thing is you can go back to other Memory Blocks, and fight bosses again or collect the Templar Coins.
Overall, its 4/5; would have been 5/5, but I felt as if the game could have been of a better standard in gameplay, and kills could have been harder. Great game still though, so a must buy.