For this achievement at the end when your on the roof of the Asylum and it gives you the option to either stay with Jenny or jump off the roof, make sure you choose to jump. For some reason when i reached the end and chose to stay with Jenny it didnt give me the Achievement. It just went to a small cutscene and then back to the main menu. I hit continue at the menu and it took me back to the point where i was on the roof. This time i chose to jump and the game continued. Got the Achievement at the end of that level. Just wanted everyone to know just in case you pick to stay with her and dont get the Achievement!