Steam is very 50/50 on what lewd you can sell. Its really up to the specific reviewer you get and a game with an anime art style is playing on extra hard mode. Your better off sticking to an ecchi style game on steam and providing a lewd path on itch.io/elsewhere which is what many games already do. There is no appeal system for being banned for sexual content unlike with other kinds of content such as AI generation, formatting errors, etc. You will also not receive a specific reason for your ban nor will have any communication with steam. Additionally steam wont allow you to reupload a similar game as either steam or their credit card's mitigation system will automatically detect games with similar branding. This is how the system is supposed to work if there are exceptions feel free to list them here

Notable examples include

• My Femboy Roomate which after debuing in a Steam NextFest was promptly banned. This game was immensely popular and memed upon with the normies and shows just because something is popular doesn't mean its safe. The game quickly rebounded on Patreon however https://steamdb.info/app/2972800/
• My Dystopian Robot Girlfriend which got banned for the titular robot girlfriend looking too much like a loli. The only reason its here is because it got mentioned in a thread. https://steamdb.info/app/1867040/

See this list of banned steam games:

• https://docs.google.com/spreadsheets/d/1aAbrEDNa2NmgntrKtij0RuxKneiFcTJisGyfMUv2nnM/edit
• https://steam-tracker.com/apps/banned

Around 2017 is when the first of the patreon crackdowns started. To this day they heavily censor what types or kinds of lewd is acceptable. See this page detailing their specific guidlines https://www.patreon.com/policy/guidelines#sexually-gratifying-works. The tldr of it is stick to vanilla, no rape, no bestiality, no incest, other /d/ fetishes like tentacles *may* be acceptable.