In the 14th stage you get a power-up that basically sets the game on automatic for as long as you desire. It seemed useful on the 14th stage so out of curiosity I activated it as soon as i could on the final stage and walked away to see what would happen (FWIW I am playing on easy). I believe 25-30 minutes later the stage is complete with 2 out of 3 stars and 99.9% of the population still alive.

I don't know that this actually says or means anything, I just figured someone might find it a bit funny :P

Hey @jdelible, thank you for the bug report!

Things are supposed to be easier with full automatic, but not that easy ;) I'll take a look at the balancing and release a patch with the next update. 

Thank you.