Throughout the game the player may pick up puzzle pieces that have a letter upon them. These letters form a simple word puzzle where the player has to figure out what all the letters put together mean. The puzzle may be accessed during a game by pressing ESC then selecting Puzzle, provided the player has at least one piece in their possession. Completing the puzzle gives access to the secret ending in Resolution by using the computer in that level.
It is unknown how the Biker can discover the password in-universe, since all the puzzle pieces are found in Jacket's levels. When asked by the surprised Janitors, he merely answers that he "used a little magic."
As with masks, there is an icon on the chapter selection screen that indicates whether the puzzle piece in the selected chapter has already been collected.
Solving the puzzle
When solving the puzzle, letters that have been left in the right location for a few seconds will turn blue and get locked into the location. Using this feature, one could complete the puzzle by simply trying out each piece in each location and waiting for the blue confirmation. Once all the letters are in the right locations, the puzzle will constantly flash to indicate completion. The puzzle screen shows empty grey boxes to indicate where letters should be placed and grey bars between the boxes to indicate what sets of letters form a word.
There are 16 puzzle pieces in total. One piece may be found in the Prelude, as well as Chapters 1 through 15.
Each puzzle piece appears as a small purple square which can be very hard to see unless one is specifically looking for them. The Rasmus mask will add a small glow around the pieces making them more noticeable. The puzzle pieces can be right clicked to be picked up. Once a piece has been picked up, it will not save to the player's save file until the chapter has been completed. The exception to this rule is if you find the last piece and then solve the puzzle. You do not need to complete the chapter for the solved puzzle to remain solved.
The following slideshow will indicate where the puzzle pieces are in each chapter.
Solution to the puzzle
To view the puzzle solution, view this page. Spoiler warning.