I can't even clap my hands to the beat, so DDR is not a game I play. However I saw a 40-something year old mom play.
While visiting Las Vegas a couple years ago, a bunch (actually, looked like three groups of friends, so maybe I should write "three bunches"

) of early to mid teen kids were playing on a side by side challege cabs. A couple of them were so good they were "showing off": crossing legs, 180 spins, 360 spins, do some facing away from the screen, ect. I think they were doing some "if you pay my quarters, I'll teach you how to play
StreetFighter DDR" too.
One of the kid's parents showed up, and I guess their son had been talking smack. The next kid in line convinced the mom to take his place. The kid to play opposite her was one of those so-good-I-can-show-off.
It was a sight to see: a forty-something, slightly over weight mom kicking the kid's butt. The look in the kids' faces were great. I think she perfected everything.