I remember him bragging about baking Steam achievements deep into his game so it couldn’t be pirated, or something like that.

I remember someone on r/gamedev bragging about doing that, only to get immediately dunked on by people pointing out that making a game dependent on steam achievements not bugging out is dumb and risky and that the literal exact same program used to bypass steam DRM in the first place can also emulate its achievement API if you just check a box asking it to do that while applying the crack.