The fish mask, Phil, which translates the game dialogue to French, is in reference to Phillipe Poisson, also known as Phil Fish, the French-Canadian game developer known for the creation of the indie game Fez.

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.