This game is a decent introduction, though I think it has plenty of room for improvement: https://adam.math.hhu.de/#/g/leanprover-community/nng4 https://adam.ma

This game is a decent introduction, though I think it has plenty of room for improvement: https://adam.math.hhu.de/#/g/leanprover-community/nng4 https://adam.math.hhu.de/#/g/leanprover-community/nng4.