For this achievement you need to complete the very first stage the Underground Cemetery. You just need to climb to the top and make it out the door. The faster you climb and the better score you get but the achievement pops either way.
Here is a link that gives details and a video for the scoring for easy, normal, and hard. Credit goes to wikia.
http://catherinethegame.wikia.com/wiki/Walkthrough:Undergrou...