This is one of the best action performer hentai game that ever play ever since Project X: love potion disaster.
I have a few suggestions can we have non zombie human enemies: Sex addicted Humans (enough sex will turn them into zombies), hypnotized females with facehuggers and weaker versions of the boss.
I do have some ideas on background elements like girls giving birth to eggs which are used as spawn points for insect larvae and an option to join the background characters
I hope you take ideas into consideration and please take your time on next update²