No, the problem here, I think, is that they aren't for playing DDR. They're for doing a bunch of obscure challenges that use the songs and the dance pad but are actually detrimental to playing the game. Silly things like play a song at triple speed, with no top bar, and the arrows appearing halfway up the screen, without missing a single step. Except for the up arrows. Hit an up and you lose. So if you're actually good enough to pass the song with a speed increase and not seeing all the arrows properly you're probably screwed because you're going to instinctively hit the ups and lose. So in order to actually do it you'd need to practice the song with those weird conditions over and over and over until you did it perfectly. And then do it for 48 other different weird sets of conditions. Sorry, but I'm just not willing or able to do that. I haven't gotten all of the achievements in any xBox 360 game yet and DDRU2 won't be the first one.
BMI: 22.01 (+0.03)
Wii Fit Age: 28 (-3)