Hi. I want to offer a few ideas, if you accept them.
Firstly, there are scales and a growth meter in the medical room, I suggest giving the character the opportunity to interact with them.
When using a height meter, the character would say that she has not grown a single centimeter, for example. Add a character trait that the character is going through because of low growth.
When using scales, make several options. The first option is clean (without sperm) - everything suits her, but she says that you need to continue to monitor the figure. The second option, when there is sperm inside the heroine, it is divided into 3 sub-variants, which depend on the degree of debauchery. At the first degree, the heroine begins to worry about the weight and hopes that the sperm will leak out. At the second degree, the heroine begins to wonder how much sperm she can still fit in. At the third, she wants more sperm.
Washing in sinks, fountains, with a water bottle. Reduces the amount of sperm inside and reduces the degree of debauchery by 1. At the first level, at school, it is not limited. In the future, this is a very rare type of first aid kit.
Add 4 degrees of debauchery in which the heroine will at a random moment give herself to the enemy, at such moments it will be more difficult to escape than with a normal capture. Make a special surrender animation.
Make a display of the degrees of debauchery on the heroine's model. So that her clothes became more and more torn, and her body was more and more covered with sperm.
Make the surrender animation more reflective of the degree of debauchery.
Pregnancy should be displayed on the model.
Pregnancy should also impose debuffs. Attack speed is lower, movement speed is lower, stamina is spent faster.
Different NPCs fuck her at the same time. For example, a guy and a girl, a fly and a dog, a slime and a spider.
Add more human NPCs. Civilians, including fat men, because they always look interesting in such games. Military, police.
Add a certain system of "infestation" to the character, and make the laying of larvae into it not permanent. I'll explain what I mean and take a fly as an example. Divide the fly by gender. The female fly lays larvae in the heroine, a different amount, not just 2. Make a quantity from 2 to 5 in one act, and the deposition always occurs in the uterus. The male fly after sex fills the heroine with sperm, as now in the vagina or in the anus. Give preference to the vagina. If a male or female fly, say, used a vagina 3 times in a row, then the character gets "infected". For a while or until he takes the antidote. While the "infection" is in effect, the heroine can give birth to 2 to 5 larvae herself, without a female fly. Only with the help of a male fly and his sperm. If a male or female has used the vagina 5 times in a row or more, then a mutation occurs and the heroine gives birth already from any sperm that has entered the uterus. Even if it is the sperm of a spider or tentacle. Even if she was fucked by a dog, a rat and a slug, in turn, a fly will still be born. To cure this, you need to look for a first aid kit or a medical room.
The hatched fly larvae should try to return to the uterus. They live there for a while and when they develop to full-fledged flies, they get out. After that, they begin to attack the heroine in order to fertilize her again.
Add a small inventory in which you can store a first aid kit, an antidote or a bottle of water. The size of the inventory is 2 or 4 cells. If you make inventory for 4 cells, then all items should occupy 2, so that the player has to choose what to carry with him. At the same time, do not limit the player in the choice of items, the path carries two first-aid kits, two bottles or two antidotes.