Any ideas for pulling this off?

[Gavin]

My idea for a level is basically you start by watching a series of monsters pass over a button paying attention to the timing. Then, after a trigger, you have to press a button repeating precisely how the other button was pressed by the monsters. And only doing this correctly would allow you to progress to the exit.

I have an idea involving a green button and toggle doors that might work but does anyone have any ideas?