A recent WSJ piece showed that actual playing time in NFL games is about 10 minutes and 43 seconds. As the article noted, football "is the rare sport where it's common for the clock to run for long periods of time while nothing is happening:"
After a routine play is whistled dead, the clock will continue to run, even as the players are peeling themselves off the turf and limping back to their huddles. The team on offense has a maximum of 40 seconds after one play ends to snap the ball again. A regulation NFL game consists of four quarters of 15 minutes each, but because the typical play only lasts about four seconds, the ratio of inaction to action is approximately 10 to 1.
Pete Townshend and Roger Daltrey were performing on stage during the halftime show for about 12 minutes, probably exceeding the time of the players' on-field efforts. The veteran rockers said as much during a press conference last week:
"We're going to be playing for about 12 minutes at halftime," he said. "But I've heard if you take out the commercials, there's about 11 minutes of playing."
"We're going to be playing longer than the players," Townshend added.
Their ages (65 and 64 respectively) mark this as a past-their-prime performance, but at least they played better than Peyton Manning.