*Credit goes to "
K4rn4ge" from Trueachievements.com for the guide*
Original Source: TrueAchievementsProfile: TrueAchievements"After beating all 50 levels of adventure mode (you do NOT need all stars for this, just get through the campaign), you will unlock a bonus level called "The List". From the main menu, click on the bonus level option and you will find this level. The credits for the game will roll during the level. You can be killed by the letters so hug the left wall so you are in a safe spot. The names will scroll in alphabetical order by last name. You need to wait until you see the name "Mary Roddy" and COMPLETELY destroy both of those words with your gun. After doing so, die on purpose and the achievement should unlock shortly after.
Some backstory to this achievement for those who are interested: After figuring out and unlocking the achievement, I was then informed by one of the devs that Mary Roddy is actually their office cleaner/janitor (hence the name and description of the achievement).
"I just wanted to add that "Mary Roddy" does appear within the first wave of names.