Yup! As long as your moving and putting in true effort and not just moving your arms, you can lose weight! I don't have this game, but I do contribute to another type of dancing. It's called Zumba. They also have a "10 day program" where you could lose a whole pant or dress size! It's a series of cardio workouts and full body stretching one day, then the next day strengthening and toning and then abb workouts the next day. "Just Dance" can probably do the same thing as long as you eat correctly and no late night snacking, cause that would ruin the hour you put into dancing! =)
Any kind of dancing, running, jumping, jogging, etc... will burn calories, which will make you lose weight.
Whether or not you will lose weight playing the game "Just Dance" depends on how long you play each day, how many days a week you play, how you dance, your eating habits, etc...
If you are eating loads of junk food all day, then it's not going to make you lose weight.
Also, I wouldn't make the game the only exercise you are getting. Perhaps one day you can go for a long walk or jog, and the next you can play the game.
Yeah it should help you a bit. It includes moving, dancing, which is a form of exersize, and that helps.
Simply.....yes. : ]