▲
1
▼
Collecting the letters found in certain levels as Biker will unlock additional dialogue when talking to the characters in the basement at the end of chapter 19. While normally they will refer to their scheme as just a game, when all of the letters have been collected, they will reveal a much deeper conspiracy present within the game.
▲
1
▼

While the translation is mostly aesthetic, the mask does add some unique dialogue for the ending of the Bonus Chapter Highball:
"Salut, je suis Wiley Wiggins! Bienvenue a fantastic arcade!"
which translates to "Hello, I am Wily Wiggins! Welcome to Fantastic Arcade!"
This is in reference to the festival "Fantastic Arcade", which named Hotline Miami as "Most Fantastic" in 2012.
Related Games
Hotline Miami 2: Wrong Number
428: Shibuya Scramble
Marc Ecko's Getting Up: Contents Under Pressure
The Talos Principle
Pepper Grinder
Omnibus
Serious Sam Double D
SNK Heroines: Tag Team Frenzy
Danganronpa 2: Goodbye Despair
Shadow Warrior
Observation
Serious Sam 3: BFE
Gods Will Be Watching
Danganronpa: Trigger Happy Havoc
A Boy and His Blob
Double Dragon Neon
Angry Birds
Rogue Legacy
Shadow Warrior
Ark: Survival Evolved
Dropsy
Mighty No. 9
The King of Fighters XIV
Sherlock Holmes Versus Jack the Ripper
Poncotsu Roman Daikatsugeki Bumpy Trot 2
2002 FIFA World Cup
SimCity
SaGa: Scarlet Grace - Ambitions
Bubsy: The Woolies Strike Back
Sonic Mania
Superhero League of Hoboken
Naruto Shippuden: Ultimate Ninja Storm 4
Garfield Kart: Furious Racing
The King of Fighters '96
The Elder Scrolls IV: Oblivion
The Incredibles
Papa's Paleteria To Go!
Raid: Shadow Legends
Van Buren
Deus Ex
Castle of Illusion Starring Mickey Mouse
Friday the 13th: The Game
Z1: Battle Royale
Just Dance 2023 Edition
Beyond Oasis
Life is Strange
Sonic the Hedgehog: Spinball
Heroes of Might and Magic III: The Restoration of Erathia
Lost Judgment
Burnout Paradise