Solve control challenges with JavaScript

Maybe it's just me, but I had no idea what the first task was until I closed the modal. Then I could see the block moving and have some idea as to what I was supposed to do. But still, not really. It isn't clear.

Maybe start by getting the user to build the block moving function. Better yet rather than obscure 'moving blocks', try to map these to real-world functions which would allow more people to understand what and why.