In HN the GAAP was mentioned several times and I still believe it deserves a place in HN2, here’s how I think it should go.
The Park itself is a sub level, like the forest, and you can enter it by going through the currently closed off tunnel in the screenshot. Through the tunnel is a derelict road that after travelling down for a bit, you get sent to the GAAP level.
Adding in a ferris wheel in this direction in the main map could help let players know where they’re going. Also making the landscape higher in that area and adding a few trees in would help mask the fact that the park isn’t actually in the main level
Inside the park, there will be burnt down rides and kiosks that are falling apart at the seams. The rides are broken and there is dangerous outdated electronics sparking. The park is set in a clearing of trees in the middle of a forest, maybe add the 2D background trees further away to give the illusion of a larger forest. The player can be provided with a flashlight inside one of the burnt down offices than can ward away the antagonist, the Guest.
The Guest will act similarly to the Forest, where he will stalk you, any buildings that have doors can be used as siege zones like the forest where you can board up the doors. Theflashlight you find here could work in a different way to how the normal one does, as it is broken and outdated, using it will make a shock of light and stun the guest if he is nearby, it will then have a cool down of around 10 seconds until it can be used again, in that ten seconds the guest will run away for a moment
The goal in the park could be repairing a ride, or maybe getting up a mountain like the early pre alphas for the game, and reaching your goal could give the player a new ending, just like the forest, the ending could grant the player an achievement just like the main ending to the game, the ending could help reveal some lore for the upcoming events of the franchise, or shed light on past events of the game.

