It's cool looking, but frankly it has nothing to do with "digging a tunnel". It's a "graphically draw a line through a sphere" app. Digging a tunnel would hav

It's cool looking, but frankly it has nothing to do with "digging a tunnel". It's a "graphically draw a line through a sphere" app. Digging a tunnel would have to deal with deep earth concerns, such as how to deal with the core, what to do with the removed material, etc.