Yes, we use DDR in PE class for grade 1-5. It is most popular with grades 1-3. We bought the game and then we play it on a DVD player and use a projector to show it on the wall. This way we have 40- 50 students participate. Each student gets a poly spot for their home base and they move from their. It really gets them moving.
I would like to look into purchasing a DDR system for my elementary school. Another PE teacher from a different elementary school in our district borrowed one from her husband (a high school PE teacher). It was a hit. So I think middle school students would like it too. Sometimes, it is all in how it is presented.