For me, the game begins at a fast pace by throwing many different and varied situations at you, changing settings, and mixing up the gameplay. What helps the best is that the missions aren't as hard as last time (or I'm just much better), and they are much shorter (same reason against it). The consequence of all this is that the game itself is extremely short, and sadly, suffers at the very end when the pace is slowed and the game extended by two extra levels that seemed a bit pointless.
Check it out at OC ModShop.