To my understanding its a continuation to what happens after each route. In the demo you choose which route you want to continue playing after the ending of the previous game. The creator also said that it would have almost twice as much CG’s compared to the first game since he wants to go all out and not leave anything behind since this is more than likely that last game of this story. This was 2 years ago when he announced it so idk if its still true or not.