Gimme A Hint Achievement
Gimme A Hint5
Use the Hint button five times.
This achievement can be done AFTER you complete the game and have obtained all of the achievements related to not using hints. From the main menu, just hit continue game and it will bring you to right before the final cut scene. Just hit the "Hint" button in the bottom right of the screen five times in a row (it does have a slight recharge time).