Exerbeat (wii) calories w HRM?

I got exerbeat today! It seems like a lot of fun. The calories burned seems high. They use the same MET system as other wii games.

For example in 45 minutes of high intensity/aerobic/etc games on wii, with some slower ones mixed in here and there, I seem to burn ~250 calories.

Exerbeat told me I burned 570 calories in 45 minutes.

Exerbeat DOES seem to get more parts of your body working at once, and has a feature where it can chart your HR if you have a monitor, but I don't.

Just curious if anyone has compared this game to a HRM. I was definitely working hard but 570 seems a stretch!

Thanks!!