The game was lost on the coaching. Denver played like they already had a lead to sit on from the start. They did nothing passing-wise beyond 10 yards out the whole game. You gotta pass medium and long range at least a little to keep the defense honest, even when those are low-percentage. All Seattle had to do was pressure Manning and wait around 10 yards from the scrimmage line to stop whatever happened.
I was watching Denver audible, then Seattle's defense would audible then they'd adjust. I said at the time, they've got him read! Sure enough, it comes out now that they did know quite a few of the hand signals and his audibles so they could jump the formation.
I don't know what look Denver's coaches expected from Seattle but they sure did not prepare for the look the Seahawks showed. On the other hand Seattle is in the top 5 best prepared Superbowl teams I have seen, right up there with the NY Jets, the 49ers in their heyday and the NY Giants in theirs. They clearly deserved the win.