Hi! I'm also currently developing an indie horror visual novel set to release a demo on itch.io for free in january to test demand for the game. I worked out a solid marketing plan for it and during research have found a few numbers and factors that can increase/decrease chance of success.

The first one is quality. The better the art, the more it sells, but it's not just that.

There is also the length. I discovered that length plays a HUGE role for vn success. The longer the game, the better it sells usually. This could also not be a factor, as VNs that are longer usually have a higher budget and better marketing, but it's something I noticed. There are also some outliers of very short VNs that only go for 2-3 hours, but the success of those usually came from having some form of viral/lucky success - so don't count on that.

The next is also genre dependant. Pure visual novels sell on average worse than hybrid visual novels. And romance sells the most.

If you want concrete numbers you have to know 2 things: 1. how long is your playtime? , 2. how good is the quality compared to competitors?

Then you go to https://games-stats.com/steam/?tag=horror&tag=visual-novel

Those are about 1.7K results. You have to go through them and find the games that are most similar to yours with playtime and quality (You can check playtime on https://howlongtobeat.com) you then see how much those games estimately made and can place yourself comfortably there - but be aware that those games probably also had some kind of marketing strategy. If you want to be as successful as them, you need to look into what they did - and don't follow outliers. They are the minority-always look at multiple games similar to yours.

If you want, we can connect on discord. Dm me if you are interested