A new ideas at 19/9:
1. I know this is a crazy idea, have ever thought about adding a "casino" into different playable area? You can earn some fap items / new rooms / new wifu "passport" through the casino.
2. Different rooms should have specific things, such as specific equipment / locker / uniform etc.
3. Similar to the second point above, you can infect the special locker and got some new ability. You can infect the uniform locker, change the girl's uniform into other clothes(or uniform). You can also use the tools in the locker to effectively assist your "work".