Den : holding the back button for more than a simple click, takes you to the home menu. If this is not working, than something must be broken :/ this must be default since beta1.

The other way is using the menu hardware button (as we didn't want to override the home feature for the tablet)

Also I believe you can hold a little bit the hardware back button as well.

Anyhow, for the beta11 backlog, the top left, takes you to home screen when on playing screen.

Br

Marcelo