Keep in mind, the dramatic tension was suppossed to be immediately afterward. Plus, take it in context. The progression of leaving unspecified location as it is being completely destroyed to fighting your way to the purifier beside the most awesome thing democracy ever created were designed to really raise the mood and awesome levels. The "anticlamctic" battle is to give a sense of relief...The Eggplant said:
You are told that you must enter the lethal levels of radiation where your father died to keep the purifier from exploding, while trying to decide if you want to add a virus to the water to kill all the mutants.
In short, it's to make the actual climax even more tense by comparison.
My moment, though, comes from Gradius Gaiden. This is one of the rare final bosses that can actually kill you if you're not careful. Entering the boss room, the first thing that happens is the loss of all your little helpers, making between you and the boss alone. The entire fight is set to One of the best boss tracks I've ever heard while the boss is constantly taunting you, as in the link. You shoot at him the entire time, but none of your weapons have the slightest effect. Eventually, he transforms into this strange sphere that glows and pulses at an increasing rate, clearly charging for a game-shattering blast. But he's finally vulnerable, and you wail on him with everything you have and you just barely, barely succedd, ending im in a dramatic explosion. Now, all this seems like a rather satisfying climax... except that it's all a lie. If you let it sit in that last stage long enough, it dies on it's own. No huge blast, just pathetic death.
