itch.io

Also, I'm not trying to put down anyone who doesn't follow these principles, I'm just trying to help. :)

As long as it sticks to the basic principles of a Metroidvania. Basically, it just has to have exploration, locks or obstacles and ways to get around them (Usually in the form of power-ups), and most of the time backtracking to find new secrets. Obviously, that's not all, but that's basically what it boils down to.