this is why its important to have a clear vision and idea what you want to do, they knew they wanted to make a Fnaf game, and for a while went with the "obviously spooky" tone, up until they decided, no, we need a different engine, and then decided, actually, we want it to be cutesy and adorable at first before we bring out the scares.
sure, there is a phase of experimentation in game-making. but the quicker one commits to a certain idea the better. this is why sequels are supossed to be improvements, not the game thats actively being worked on.