This looks like a much better idea.

I would continue working in this. I have some feedback to make it harder for robots and easier for humans. Consider this as some quick ideas that should be elaborated (and they may be wrong):

- Move the letters in opposite direction to the windows and maybe rotate them or make them move inside the canvas. - Make the windows appear in randomize locations but move them faster. - Make the blacked part change colors.

I think this is a very, very good way to make a turing test. Congratulations.