I do not play rpgmakers very often, but i do know that they tend to be a lot smaller, like really small, under 100mb, and some even have a playable web version.
You claim to use standard assetts, that must mean to my naive ears, that you could export a version that does not require the assets to be bundled and just need the rtp installed. I saw such and it was like 10MB. Bundling them is of course better for some players, but why not offer both.
Your game has 800+MB. So I see three possibilities. Stuff is going on I do have no clue about. You packed a lot of unneccessary stuff into the game in a very inefficient manner. Or you do have content that is not standard assets, but you do not proudly make screenshots and advertise the fact.
But if I understood correctly , you do have inflow from the social media. Just not a lot of interaction.