A very simple and elegant way to pull off an un-winnable challenge - like a true street con of the 21st century! The virtual shells work fine (though sometimes they move around a bit on their own, as if trying to snap to a grid). Being able to customize the sequence that starts the gaff means you can change it up so the pattern is not as recognizable if shown again at a later time. A truly clever idea, and one I can't wait to present to a magician friend of mine. I am sure he won't trust it, being virtual and all, but since there is no obvious hidden button or tilting or anything else easy to detect, he won't know how the scam works. Good job!