It's quite well done despite the lack of joints or observable entry (I've always been a fan of - especially when it's showing anal - penetration that's either fought for or animated in). Regardless, the game would definitely benefit from one of two things if not both:
1. A way to back out instead of completing the scenes if you wanted to choose a new option (for those who like to see all the options and look for their favorites)
2. The password system for aesthetic changes incorporated into either surrounding options for easy access inside the animation or (in combination with the first suggestion) an option selection screen prior if immersion was a goal
The idea of passwords for aesthetic changes creates an unwanted hassle in my opinion, and if none of the passwords were known the game would be extremely short and far less interesting (so I appreciate you posting them). However, if your goal is to make people work for the changes and have a sort of "discover" system might I suggest a selection screen with blacked out options with hints toward the password OR an achievement screen with either hints or some sort of criterium to unlock the new options.