I've only played 15 minutes of it, and I am not in the greatest shape at all, really, so I did break a sweat.
Hula Hoop is my favorite activity, followed by Rhythmic stepping. Aerobics is my focus, since I'd like to get my heart a little healthier and trim down. Hula Hooping requires endurance as well as balance, and stepping is like DDR with directions and two buttons.
Haven't tried Yoga or Strength yet. The Balance games are pretty hard.
The board itself is amazing. Very sensitive surface, can detect the slightest change in balance. And the analysis they give you when you first start up is pretty nice, too. Well, cept for the parts where they say "Oh look you're not doing so hot with your BMI" if you're not in good shape.
All in all I'd say this is gonna do quite a bit to help heartrate and muscle training. You can feel the burn after just a couple exercises.