Alan Wake Remastered (UP)

Ending on Normal difficulty will also open up the achievement for easy difficulty.
Here is 100% complete guide to all achievement/collectibles and full game:

This is simply unlocked once you hit the credits. The original game had this achievement stack depending on the difficulty chosen, so I imagine this unlocks if you beat it on Normal (hard in the original). Beating the game unlocks chapter select within Episodes, but only for Easy.