I'm beginning to homeschool my kids in computing, and we are pairing up chapters of The Elements of Computing System (the Nand2Tetris book) with games that teach similar skills/kinds of thinking (Human Resource Machine, Comet 64, etc...), but we didn't find anything to supplement the first two chapters (where you build basic chips up to an ALU in HDL). I ended up starting creating a kind of browser based kata for those chapters here:

https://virissimo.info/build-your-own-alu/

LMK what you think.