Ah okay, I didn't realise that was how it would work.
The main thing that I seem to stumble up on is this:
Here's the issues:
1) When you click on an instance of the blue box it changes the animation to red, when you click on it a second time this animation goes much quicker and I'm not sure why?
2) The green line always appears on the wrong blue box from the one I click on, I'm obviously messing up something with the scoping and would love to learn what I keep doing wrong.