Malik goes from being a basically mute guy who falls afoul of the law to being a self-assured, educated criminal. The simultaneous development of the criminality and the self-assurance is the really fascinating part. You're always cheering for him, even when he's doing some pretty fucked up things. Partly, this is because he retains a kind of innocence - there's an absolutely breathtaking scene where he flies on an airplane for the first time, but there's also this moment in a scene where he's basically executing some guys where it suddenly switches to silent slow-motion and he's just kind of floating in this pile of bodies in a vaguely Christ-like way. It's really impressive.
This isn't something that I tend to notice much, but the sound in the movie was phenomenal. There are, to my recollection, only 3 songs in the film, but each of them is so fantastically effective in setting the scene. Aside from those though, the sound is kind of... barren, in a way, which makes it somehow more powerful. Really impressive stuff.
It's not a perfect film - some of the sideplots are slightly less compelling, and it feels a bit cluttered at moments, but still, it's a really incredible movie. Very much worth seeing - on the big screen if you can, because seriously, visually, it's a masterpiece.