First time poster here, but this game was such a chore to complete that I'd figure I'd leave my thoughts here (I'm also including my Map which has every girls' location and the location of Bathrooms and Gyms):
1) Some sort of fast travel system beyond a teleport to the entrance would have been super useful. To see all the scenes you have to backtrack multiple times, and clicking through the maze multiple times isn't fun.
2)Some indication of where locked doors are is definitely needed. I spent a lot of the time just retreading through the maze in order to find where the new door has appeared. The character should be able to see that a door is locked, and so the player should know about its existence before finding the key.
3)The GIFs are inconsistent when I don't think they have to be. For example, Krissy's hair color changes between gifs, and I know gifs exist where her hair stays brunette for the BJ gif.
4)As mentioned by other posters, the background pictures could use more variety. The map is huge, and you spend most of the game treading through empty space. It would also provide landmarks for players to navigate by.
5)On the subject of background pictures, I think on the long stretch between Anissa and Rachel (it might be on one of the other North-South Corridors) one of the background pictures failed to load.
6)Players should be able to select gifs individually from the start rather than having to re-click through already seen gifs to get to new content. The player can see the same Blowjob gif 3 times if they see a character soon enough. It gets tedious if you're exploring for long enough because you have to pause or mute each gif to prevent the sound from overlapping.