Here's my instructions and signal tester on Scratch for a homebrew 8-direction controller:

http://scratch.mit.edu.ezproxyberklee.flo.org/projects/10809793/

It works pretty good, especially if you tinker around with it and modify it.

Any feedback?

Also, if you own or use a MaKey MaKey, is this project easy or hard to follow? What could I do to make it easier to follow?

I'm thinking about remixing the design myself and making a special controller and some Scratch games for it. This controller would be a long narrow cardboard box with multiple 8-direction joysticks and would be for unique games. One game I was thinking of is a game where you have to quickly switch back and forth from controlling your character and enemy characters by using different joysticks. I would program this by doing my signal tester code along with assigning an extra button for each additional controller (controller one example: “when up and only up is pressed..” controller two example: “when up and space and only up and space are pressed..”) and wire the extra buttons into each additional controller.