that seems exceptionally odd, since mindustry doesn't follow that whole thing.
They don't have to fallow it because they aren't selling steam keys on itch.io. They are giving the game away and leaving a link in the description to there steam page so you can buy it on steam. Witch is a good way to do it. I wanted to sell the steam keys on itch.io though because if I sell the keys on here steam doesn't take 30% of the sale i only have to pay itch.io 10%. Also on itch.io if i wanted to i have access to a slider that alows me to decide how much of a cut itch.io takes i can let them take 50% or i can give them nothing. So sence im selling the steam keys on itch.io I have to fallow steams rules or I won't be able to sell my game on steam. And there number 1 rule is that you can't sell steam keys for cheaper then they are available on steam. I left the full game as a demo so if you don't want to pay you can still play without having to pirate the game and possibly get malware. I understand it's strange so I'm trying to be as transparent as possible as to why I'm doing it this way.