Gameplay is, I think, the most crucial aspect of a game. I mean "game" is right there in "gameplay." Sadly it's where Call of Duty: World at War: Final Fronts disappoints the most.
Call of Duty: World at War made the tired World War II setting work through innovation. The sniper level in which you hide amongst dead bodies and time your shots with passing planes? Sure, it may have been a mix of Enemy at the Gates and the sniper level from Call of Duty 4, but it was still great, as was the ensuing chase after you're discovered. Call of Duty: World At War: Final Fronts contains none of that innovation and excitement, delivering an experience that "by-the-book" is too nice of a term for.
In fact, the only thing separating it from past PlayStation 2 Call of Duty titles is the addition of the flamethrower, but even that is somewhat ruined. World at War at least made you wait a few missions before letting you burn guys to a crisp and the anticipation was sweet. Here, however, all of that magic is killed after you get the flamethrower in the very first mission. I understand that it's a flamethrower and that's awesome, but these things have to be handled with care, you know?