Catherina Alone

Your images are way too big. Use lossy compression exactly as you would for photos. I hope those 1MB+ files are not your master images, because they do not look very detailed for their resolution.

You could have better quality images for 1/10 to 1/5 the file size. PNG is the wrong file format for the content you make. And this factor 5-10 is not an exaggaration. Try a JPG with setting 90, it will be about 20% the size and you will not see the difference. Especially with the low details you have you can easily go down to 75 which is about 10%. Or use webp with lossy setting to achieve the same size reduction. 10-20% of your current average image size should be your goal. And if your master files are higher resolution, even better. Use those and make files that are only 20% the current size.

Add more tags that describe the nature of the visual novel. At first glance and after playing this looks like it might become slice of life, drama, corruption, female protagonist, management and so on. In the current state it is more a kinetic vn with no actual choices, other then to watch or not to watch a scene. You currently only tell us, it is an adult vn with three tags that mean the same. You can have 11 tags and only use 2. Use the tag "milf". Itch has free tagging and a milf prot is a rarity. https://itch.io/games/tag-female-protagonist/tag-milf 

And make sure people know who the protagonist is. The husband being cucked will bother some people, no matter how you spin that angle. If he is not essential to your story, consider removing him somehow from the story. She can also have fun because she is bored and not because her husband encourages her.

The beginning is a bit confusing. The first decision is not the decision of Cat, but of the visting friend. Also the exposition fails to mention the husband. And the visiting friend is fantasizing about her. We see his pov. Not she is thinking about what he might be fantasizing about or fantasizes herself.

The conversations she has with Seb might be more fitting with a female friend of her's she would be asking for advice. Unless of course you aim to deliver the cuckold fantasy. Like when he tries to whore her out for a business deal and then promptly falls asleep while she is screwing the business partner.

I do not like your current usage of audio. Feels more like a jump scare and out of place "borrowed" voice overs from dubious sources.

We shall see, where the game is going. I like management games with corruption mechanics. I dislike kinetic novels. But you should create what is most fun for you to create.