You can get both "Face-Off" and "Merciful" achievement in one run. Saving you a second playthrough. When you get to the part in the game where you choose to shoot the caretaker or not. Shoot him to get "Face-Off". Really quickly hit
and quit the game. Reload the game again and continue your save. The caretakers body will be gone but carry on for a minute or so and "Merciful" will pop.
Other guides say you cant do this but you can. I unlocked both of these achievements a minute apart and the whole 1000g in 60 mins.