firstly it has a story line beyond killing random people(possibly one of the few games to do so).Secondly the graphics are incredible and are the best example of how much better the new consoles are than the old ones. thirdly the controls are easy to master and it comes with a helpful tutorial at the start. Finally its fun to play, i got it around january 2008 and even now i still play it sometimes and enjoy it.
The only slight downside is that it doesn't have online play, but aside from that it is a superb game which i would recommend you buy.(possibly not from this sight as you can get it in game for around £30).