[scotteh]

In a similar vein, NandGame (http://nandgame.com/) is an online game where the challenge is to progressively build a microprocessor, starting from simple logic gates.

Show HN thread from a couple of years ago: https://news.ycombinator.com/item?id=17508151

[km3r]

I really liked https://asteriskman7.github.io/dldtg/

Its a cookie clicker type game mixed with an almost VHDL like circuit design language.