I can't believe i came to this page to find a bunch of people suddenly bashing Nacho Sama and requesting refunds because... there's a steam version available now? The game cost like $3 and you still have a fully playable game that will remain the game you got into and love.
The steam version is a separate version with changes from the original. Available as a separate purchase so you can play the new version or the one you already enjoy.
For $3. This isn't a AAA big studio $70 title, it's barely a coffee. Relax. Buy the steam version and try a slightly different version, or load up your itch copy and play the game you love. You have what you paid for what is y'alls problem?