BitWise

Close the loop, and the lamp lights.

That is the first level. By the seventh chapter a machine you wired listens to a blinking beacon, tells the dots from the dashes, and lights the lamp marked A.

BitWise is a puzzle game about electricity and the machines people made from it. You place parts on a bench, wire them by hand, and the circuit runs on a real simulator. The grader has no answer key. If the lamp lights, current reached it.