I was playing around with a tiled world with physics enabled.
Now this is not really something a phone would handle, and sometimes barely my PC with the avalanche() function turned on, but it's good fun and maybe it can give some ideas. Until we get the ability to check images pixel by pixel.
The tiles are set to 5x5 pixels, even at 4x4 it gets too heavy to run on my poor laptop so forget pixel perfect. However there is lots of optimizing to do, for instance every tile doesn't need physics enabled just the outer layer, which would be easy to fix.
So check it out and if anyone wants it I'll mail the source, who knows.
Drop bombs with a click on the mouse, also try placing them under ground for more effect
My hovercraft is full of eels