The Long Dark is a first-person survival game where you must fight to survive, both figuratively and literally, in the frozen Canadian wilderness. The achievement The Will To Live requires you to survive 500 days in a single Survival Mode game.
Five-hundred days is a daunting task to begin with, but when you factor in all the things this game throws at you it seems like an eternity. See, The Long dark isn't just a survival game where you manage your health and can wait out the time. No, in this game you need to manage your warmth, hunger, thirst, fatigue and all those silly little things that keep humans alive.
To gain this achievement, you're going to have to be one with the wilderness. You'll need to plan ahead, hunt to secure enough food, scavenge to secure enough materials and pray a bear doesn't eat you at day 499. Seeing how every game is different, with all items, tools, food and animals spawning in different locations it's hard to even go in with a plan.
Even when you turn to a guide to help you, you'll be met with a wall of text. Those guides will go as far as telling you how many hours of the day to sleep, how much to drink and how many calories to intake in a day. Yes, you need to count your in-game calories to make this achievement work.
This has only been accomplished by a handful of gamers, and is sitting at a pretty 0.01% unlock rate on the Xbox.