The movie wasn't bad. It was better than I expected actually. There was a big issue about Jake Gyllenhaal being a Persian prince. He has a beard. That's Middle Eastern enough for me. So let me review.
The bad points come first. The main characters in the story speak in a weird accent. Is it Middle Eastern? British? It threw me off at first. There was a romance subplot but I'm biased against romance. The story gets pretty stupid at times. Sometimes you're left wondering how the bad guy or the good guys could act so idiotic or trusting. The female lead is eye candy enough but spouts exposition far too much at some points.
Now, the good points. The good thing is that none of the weak parts of the movie suck enough to drag the movie down. Even if you don't like the romance, the comedy relief (which I actually liked) or the story, it's actually all tolerable. But if you happen to like some of those then you'll like this film. The action was pretty sweet. There was a lot of Parkour going around with jumping, running, leaping, swinging, more running and fighting. That's pretty much the only clear relation it has to the video game.
Try not to approach this film as a video game adaptation but an action movie because that's what it is ultimately. It's a pretty solid action movie too. It's a crowd pleaser with something for everyone. Even the parts you don't like are easily ignored. If you're not into action, like if your a woman or something, there's always Jake Gyllenhaal's chest to look at.
Watch it if you want some fun.