[sergex]

Author here. Yeah, the first level is special and perhaps half-baked. It felt like cheating to start with the NAND-gate as the atomic component since transistors are not NAND-gates. So I start with electric relays (since they logically correspond to transistors but are easier to visualize). But I didn't want to get into realistic simulation of electronic circuits with all the complexity this entails.

May I ask how you would have preferred to solve the first level if the game didn't have limitations?

[theamk]

Two relays' outputs in parallel (A.K.A. "top half of CMOS NAND cell"): https://commons.wikimedia.org/wiki/File:Relay_nand.svg

(In real life, I might put a diode OR + single relay-based inverter, but that's too far into analog logic for the essentially digital game)