Game secretly about TDD. You start with a empty space with all sorts of things on it and it looks really confusing, but the text bubble says "Woah hang on, that's a lot of stuff. Let's start slow and ignore all of this", and he gives you a single requirement that goods go from source A to sink A. Just a nice straight line of pieces.

You run it, and it works. At that point, unlike other games where we clear it and go to the next puzzle, everything stays where it is, and the next challenge gets added to the bottom. Things should go from source B to sink B. Things still need to go from source A to sink A, though. You just have two tests now.

Then things can ramp up, like "Source C has a lot of weird stuff in it. Some of it should go to A, and some of it should go to B". Again, though, A still goes to A and B still goes to B.

By the end you've built up a large complicated thing by going through the steps.

I'm thinking the name should be something like Tango Delta Distribution or something to make TDD...

Other things that might happen:

• Some things need to be held so they can go together because sink D needs A B A B A or something.
• Maybe some things need to be packed and repacked (kinda like spacechem here, but that's likely alright)
• Later, things change and A is now not only providing A, so you have to filter that too.

I like the constant growing system, and the concept of giving people all the tools at the start and telling them "Just ignore these for now..."