You can update games on your switch in SX OS or other CFW without going online. (You need to disable Airplane mode).
You need to have the original cartridge or atleast have the tile on the homescreen or have had the game inside your switch at any point.
This can also be done with another user's...
Only thing drive me crazy is all these new horror games nowadays is its so dark, all time. I can't even play them. I understand they trying to create spooky but be creative a little, not just darkness with pop out scare scenes.