Just an idea... maybe players could unlock certain perks or doors by playing carnival games or completing objectives?
I'm a man with a lot of free time on my hands, here's some ideas
Deadshot: Shooter arcade type of mini game, (just like the buried easter egg) but you need to get a certain percentage of headshots to get the prize, but you have a certain amount of time before the targets go back down.
Stamina-Up: Mini game that tests your speed. Somewhat like Samantha says but there's a screen that plays a sequence of random numbers, and you have to input the numbers on screens to keyboards that have numbers labeled on them.
Electric Cherry: There's a broken bumper cart station where the carts are scattered around broken and what not except for one. You have to go around finding little batteries or little energy filled bottles (anything idk) to re-power that cart. (Tbh idk where I was going with this but I was thinking of the carts that are connected to a wired ceiling)
Jugg: This can be like one of those strength tests but you're missing the mallet, you would have to go find the mallet somewhere in the map and hit the machine.
Quick Revive: Idk what attraction this could be but. (Co-op) To activate the machine you would need to push a button, and right away have a player go down next to the machine and revived. (Solo) This can just be more of a zombie soul deal.
Mule Kick: This can be at a sight seeing tent. To "see your future" you would have to find a backpack somewhere around the map and give it to the teller, after you give them the backpack you would have to sacrifice a gun of the players choice. (I thought backpack because where else would you keep that 3rd gun lol)
Speed Cola: (Tbh I have no idea for this) This can be more of a timed thing, for example if you hear a hawk screeching that indicates when you can start the mini game (but just to make it easier the cry or whatever noise there is would be louder closer to that attraction and would sound weaker the farther you are from it). In this you would have to hit a button around when the hawk cries, after that you would have to quickly hit signs in a particular order as fast as you can or else you lose and you have to wait for the next hawk cry.
Doubletap: At any booth there's a hidden rag doll or any model that you would have to shoot a certain amount of bullets at. (For example a whole b23r clip to their body).
Tombstone: Again zombie souls at a head grave hidden at an attraction.
Again they're just ideas and would be cool to see these actually work.
And all these challenges after completed would shine a perk bottle at the attraction according to however many players there are. (OR to be simple they would just power the machines).