Really? I mean I don't know exactly how the game is implemented and what language it is made in so this very well could be impossible, but I feel like it should probably be possible. When you save a file of course you still have the saves on the save slot, but the game could also generate a number code and have numbers that represent what the player has and hasn't done. For example a 12 digit code where like one is Brownie, two is Fia, all the way to Puck being 12, and if the 1st digit is 0 then that lewd scene hasn't been unlocked and if it is 1 then it has been unlocked. Also, creating it wouldn't be too difficult if you just make a dictionary and have the key as what it is representing and the value as did the player complete this (again I don't know the programming language so I don't know if it exists in the language the game is coded in, but even without dictionary just a simple list, vector, array, etc. would also work by putting the key and value in two separate lists, vectors, etc.). Then when the save code is put into a certain input then using the numbers in the code (obviously it will have to be longer than 12) it can determine what the player has and hasn't done, then generate a game based on that. Sorry for such a lengthy comment side!!