I see a lot of great potential for this game. I feel like there are some QoL changes & content you could add to it:
- More types of girls -- perhaps with different colors of hair (like pink, red, blue, purple, green, white, etc.) and different types of behaviors indicated by their clothing (Gym uniform: fast runner / With headphones or earphones: Won't run away from seeing tentacles or raped girls / With glasses: Will stop walking periodically because they somehow drop their glasses / With a jacket on or carrying heavy things: slow walker / Carrying a bag or books: Staying longer at the lockers (cuz they probably wanna get stuff), etc etc.). Maybe also add different face expressions when they're being raped.
- More voice types (could vary based on the girl's hair color)
- An animation gallery for every girl -- only unlocked once you capture a certain amount of a specific type (probably a lot)
- An option to keep captured girls in the lockers (both before and/or after viewing animations)
- A currency system (earned by capturing girls) that could be used to buy different types of animation, more lockers in the hallways, different settings (maybe bathroom with tentacle toilets could be next?), etc.
- Building off of the currency system: An "aftermath" effect (purchased via game currency) -- where raped girls could lure in other girls (their friends, logically) to where you currently are; the friend they bring will be the same type as them. Makes it easier to target specific types of girls. Additionally, you could implement an option where the raped girl can lewd their friend inside the locker instead of with tentacles (Yuri is always appreciated in my book :3)
- A feature that lets you capture multiple girls at once (whether into different lockers or in the same locker is up to you) so you can view multiple animations at once. Purchased via game currency.