Why exactly has Steam denied your game? I've seen 10 times more grotesque content being allowed on Steam, and you already have one game on their platform.
10 times more grotesque, and also, 100 times more low-effort shovelware or asset flips. Had Valve accepted Archipelagates, we wouldn't be having this conversation.
I have no experience with dealing with Valve, but whatever the cause was, there has to be a way, and I'm sure someone could help.
(As for itch, free demos are not unlisted, and the demo can link here.)