how do u do the unlock climax achievement

[DaHrtOfDaWhtDrGn]

Ok I heard from a few people u can unlock climax achievement along with hard by using the cheat on the pay phone my question is how do u unlock the difficulty achievement, do u have to beat the game first with it on?

[Ademus XP7]

yeah u pretty much must beat chapter 1 through the epologue on a difficulty to unlock every difficulty achievement. FYI no level acheevs unlock on easy and lower