https://www.gamespot.com/articles/far-cry-5-has-a-secret-ending-like-far-cry-4-this-/1100-6457634/

Far Cry 5's campaign can you run more than two dozen hours, but you can actually see the credits after around 10 minutes if you take advantage of an Easter egg of sorts. Just like in Far Cry 4, you can "complete" Far Cry 5's campaign in short order if you do something unexpected.

As you can see in the video above, one of the first major decisions you'll have to make is whether or not to cuff cult leader Joseph Seed. If you refuse, after about 90 seconds you'll trigger a sequence that ends the game. Pretty sneaky, Ubisoft!