Lemme just say first, I HAD a 5 star park and i love this game, but the NPC's are literally the only thing that is ruining my park from going 5 stars to 2 and a HALF!
The NPC's are all stuck inthe back. I had to completely delete an outer money farm because they all got stuck in it and it lowered my stars. My park now still stands at 3.5 stars