You should take pictures of the model(s) with a solid background in studio and the program can use different bacgrounds. Less pictures needed. Some positions in different outfits and some for the endings. That's all.
I am a programmer so I can tell you the coding of such a game is extremly easy.
No need for .NET. If you want to create a web-based game it could be done in simple HTML+Javascript but PHP is much more better. (if you made in simple HTML the players can download it too, but php needs a server)
I think, the most difficult part of the creation is the storyline script.
At first you have to create a very well documented and precise storyline. After that taking pictures and creating the code should be done at the same time.
If you really want to make such a game I can offer some help in programming, but I don't have much time.
