We just wanted to point out that on Honeycomb tablets, the “action bar” is always available to go back. In Spirit, the bar appears on the right hand screen (as three dots) because the game is naturally portrait. During game play, the bar is in what Google describes as “lights out” mode and appears as three dots, but you can tap on it at any point to reactivate it, and that then gives you access to the usual ability to go back. If you hit go back from the main menu, you will exit, just like any other Android app!
I’ll chat to the developer of the game and see whether he thinks it would be worth adding an additional exit button although I think the idea was not to clutter the screen!