Forest played through but not a creative mode?

I played the forest in Peaceful Mode. The boss and everything was there. What is it? I played it over PS4. Maybe it? Or at the mode? But I have read on the Internet that several have done so and had the creative mode anyway.

You also have to shoot the plane?

Do you have to necessarily that there are 2 options

Guess already

Because you can then continue playing

OK thanks.