The first game is really good but this game completely obliterates it. It's probably the best example ever of a sequel that transcends its predecessor. Every aspect of the original is improved, and any complaints you could make were addressed.

I'm not ashamed to say that this was basically the only game I played for years when it came out. I wish it still existed in its entirety, but with the servers being down it's hardly the same thing anymore. Still very much worth returning to though, even if its just for the campaign or to fiddle around in the level editor.