People just kept falling off the map, I need to contain their curiosity.

Just add packs of wolves that eat any players that leave the sledding area.

I'll make it the most gruesome death

I think go to sea from now. Please don't find me.

The moose take you in as their leader, and an entirely new secret video game starts up where you have to manage an entire moose colony, organising gathering trips, scouting parties, all while teaching them how to snowboard.

ah yes...the 'ole "make another entirely new game" idea

a simple ski resort fence like this is what came to my mind immediately easy enough to make a texture for?

Killed by the guardians

You must unleash an ancient terror.

I agree that a rock wall would just make the area feel claustrophobic. Im a fan of letting the players go out quite a fair distance until they're enveloped by a thick snow fog and wake up near the border (imo with a cute sleeping anim where they wake up with a popped snot bubble)

I was gonna suggest a cryptid of some sort but my second answer was your mother and the ski patrol come and get you with a 5 minute lecture on staying on the path or a cryptid will come and maul you or something.

snow storm time