The choices do, beside to choose which side girl you want or not, also change the way of the Emily ending also. There is a love and a corruption route with her with different scenes.
I also would love additional endings with some other characters, but to be fair the dev was clear about that from the beginning. And adding multiple routes for the other girls to this game would slow down the already very slow developement even more. Well, and so far the game feels actually more like it has three+ routes anyway (2xEm, Ash, and a kinda additional one with Sam).
So take the game as it is (with one of the Em endings and probably a "lonely" ending without her) or unfortunately search for another game if that is a no go for you.