Then make the entire game paid, That's the dumbest most useless excuse to make money I've ever heard. no child would be on itch anyway and if they were I'm sure they wouldn't be looking for stuff like this or even finding it accidentally.
Android devices are much more accessible. Windows devices are generally shared amongst family hence why it's free. As in parents are likely to find it installed. Minors frequent itch quite often since the VNs are generally pretty cheap and easy to get into. A lot of Pokemon fangames made with RPG maker made it big on here at one point as well. Ex. Pokemon Mineral.