Most of the JP playerbase dont read English so marking to them is like switching your phone to another language. Visual novels have two things going, creatively and story, if you can make a fun interactive game, you have a fun game or if you make a story the people will want more from the story. This is also true for books, people will look for their kind of book . I played your demo game for a bit to see your visual novel, it has many lacking features of visual novel.

There are no characters, you dont need characters but people will expect characters such as people expect actors in a movie. words are too small, way too small and they dont have that feeling of being read. no sound effects; you cant just rely on music and background. Basic renpy UI look, I think you selected a look and didnt do much.

Clearly the ads arent the problem, its the game being bear-bones, its a visual novel but lacks many visual novel novelty.

In my opinion you just cant push people to buy your visual novel (or any kind of game) without "branding" them first (i.e: let people know about your product). This can't be done in one night, obviously. You need to plan it carefully with long-term marketing strategy. Your product does not look appealing for most of visual novel fans (I speak here because from my experience, general visual novel fans looking for something more visually appealing like nice graphic and characters, and maybe some fanservice, before anything else). I know that several visual novels sold deviates from that pattern, but it's very, very little example and it's hard to expect that from relatively unknown creator. Take a look of the example of popular visual novel and why it's sold well, and maybe you can think from that.

Hey there Roomah Gaming,

I just finished your game last night and recorded almost 2h of gameplay and reivews, wil do my best to post it tomorrow (you commented on my post in case you dont remember who I am)... and I must say it is great and amazing story you have here.

Tomorrow you will be able to see my review, all left is an upload and to write down my thoughts about your game.

Here is the thing, visuals novels like this should be directed to not just normal gamers, but to readers, so better look for a liberary or an online liberary to run your ads there... however, since I am seeing that you have a problem to market your "SWEET" game, I might do something about it ;)

Best of luck, Zakaria Ghorfati.