I started the game by pressing 'touch to begin' and cpu usage has settled to around 50% (but it fluctuates 30% - 49%).
When I say that it is consuming memory I mean its actively consuming memory over time, if I leave it for a 10 minutes when I go back to the game I get a black screen, and have to force the app to close before I can use it again. However if I switch to another app and go back immediately, the game starts again i.e. it doesn't suspend, it exits.
I wish I had another android device to test this on, I have to assume its an issue with my particular hardware/software, otherwise I would expect to see other people reporting the same issue, as it is quite an obvious problem.