All of the masks in Hotline Miami are unique and change up gameplay, so I decided to make a video covering all the different masks. Below is a Wikia link to all masks and below that are mine
Wikia: http://hotlinemiami.wikia.com/wiki/Masks
NAME: Richard
ANIMAL: Rooster
MASK DESCRIPTION: None
GAMEPLAY: No special abilities
UNLOCK: Default mask
NAME: Rasmus
ANIMAL: Owl
MASK DESCRIPTION: An Eye For Secrets
GAMEPLAY: Adds a glow effect around Puzzle Pieces and Masks, making them easier to spot
UNLOCK: Obtained by achieving a high score in ‘The Metro’
NAME: Tony
ANIMAL: Tiger
MASK DESCRIPTION: Fists of Fury
GAMEPLAY: Killing blows from fists for all enemies (Excluding Fat Thugs and Bosses)
UNLOCK: Obtained by achieving a high score in ‘No Talk’
NAME: Aubrey
ANIMAL: Pig
MASK DESCRIPTION: More Guns
GAMEPLAY: All Weapon Spawns are more likely to spawn Firearms
UNLOCK: Obtained by achieving a high score in ‘Overdose’
NAME: Don Juan
ANIMAL: Horse
MASK DESCRIPTION: Lethal Doors
GAMEPLAY: Knocking a door into an enemy will kill them
UNLOCK: Obtained by achieving a high score in ‘Decadence’
NAME: Graham
ANIMAL: Rabbit
MASK DESCRIPTION: Walk Fast
GAMEPLAY: Jacket walks slightly faster than usual
UNLOCK: Obtained by achieving a high score in ‘Tension’
NAME: Dennis
ANIMAL: Wolf
MASK DESCRIPTION: Start With Knife
GAMEPLAY: Jacket spawns with a Knife
UNLOCK: Obtained by achieving a high score ‘Full House’
NAME: George
ANIMAL: Giraffe
MASK DESCRIPTION: Look Further
GAMEPLAY: Allows Jacket to look a lot more further away than usual
UNLOCK: Obtained by achieving a high score ‘Clean Hit’
NAME: Ted
ANIMAL: Dog
MASK DESCRIPTION: Dogs Don’t Attack
GAMEPLAY: Dogs will not attack or pay any attention to Jacket
UNLOCK: Obtained by achieving a high score in ‘Neighbors’
NAME: Rufus
ANIMAL: Elephant
MASK DESCRIPTION: Survive One Bullet
GAMEPLAY: Jacket won’t die from the first bullet
UNLOCK: Obtained by achieving a high score ‘Push It’
NAME: Rami
ANIMAL: Camel
MASK DESCRIPTION: Extra Ammo
GAMEPLAY: Adds 1/3 more bullets to the magazine
UNLOCK: Obtained by achieving a high score ‘Crackdown’
NAME: Willem
ANIMAL: Monkey
MASK DESCRIPTION: Rip And Steal
GAMEPLAY: When performing a ‘Standing Execution’, Jacket will automatically equip the weapon the enemy was holding
UNLOCK: Obtained by achieving a high score in ‘Hot & Heavy’
NAME: Peter
ANIMAL: Unicorn
MASK DESCRIPTION: Quiet Gunshots
GAMEPLAY: Reduced gunshot noises (Doesn’t make it silenced)
UNLOCK: Obtained by achieving a high score in ‘Deadline’
NAME: Zack
ANIMAL: Frog
MASK DESCRIPTION: Longer Combo Window
GAMEPLAY: Makes the Combo Multiplier last longer
UNLOCK: Obtained by achieving a high score in ‘Assault’
NAME: Oscar
ANIMAL: Mole
MASK DESCRIPTION: Darkness
GAMEPLAY: Applies a Red Filter to the game (Doesn’t affect gameplay)
UNLOCK: Obtained by achieving a high score in ‘Vengeance’
NAME: Rick
ANIMAL: Fox
MASK DESCRIPTION: Good Shot
GAMEPLAY: All enemies will die in one bullet
UNLOCK: Obtained by achieving a high score in ‘Safehouse’
NAME: Brandon
ANIMAL: Panther
MASK DESCRIPTION: Walk Faster
GAMEPLAY: Walk slightly faster than Graham
UNLOCK: Obtained by achieving a high score ‘Fun & Games’
NAME: Charlie
ANIMAL: Octopus
MASK DESCRIPTION: More Melee Weapons
GAMEPLAY: All Weapon Spawns are more likely to spawn Melee Weapons
UNLOCK: Obtained by finding it in ‘Safehouse’
NAME: Louie
ANIMAL: Chameleon
MASK DESCRIPTION: Hard To Spot
GAMEPLAY: Jacket won’t be detected unless he is extremely close to enemies
UNLOCK: Finish the game with the normal ending
NAME: Phil
ANIMAL: Fish
MASK DESCRIPTION: French Translation
GAMEPLAY: All Dialogue is in French
UNLOCK: Obtained by finding it in ‘Resolution’
NAME: Nigel
ANIMAL: Bat
MASK DESCRIPTION: Reversed Controls
GAMEPLAY: Controls are inversed (Up is down and down is up, etc)
UNLOCK: Finish the game with the secret ending
NAME: Earl
ANIMAL: Walrus
MASK DESCRIPTION: Survive Two Bullets
GAMEPLAY: Jacket won’t die when hit by the first two bullets
UNLOCK: Obtained by finding it in ‘Overdose’
NAME: Jones
ANIMAL: Alligator
MASK DESCRIPTION: More Gore
GAMEPLAY: Kills and Executions are more bloodier
UNLOCK: Obtained by finding it in ‘Full House’
NAME: Carl
ANIMAL: Locust
MASK DESCRIPTION: Start With Drill
GAMEPLAY: Jacket spawns with a Drill
UNLOCK: Obtained by finding it in ‘Push It’
NAME: Jake
ANIMAL: Cobra
MASK DESCRIPTION: Killing Throws
GAMEPLAY: Any thrown Weapon will kill enemies
UNLOCK: Obtained by finding it in ‘Hot & Heavy’
NAME: Richter
ANIMAL: Rat
MASK DESCRIPTION: Start with Silenced Uzi
GAMEPLAY: Jacket spawns with a Silenced Uzi
UNLOCK: Obtained by finding it in ‘Assault
NAME: Russell
ANIMAL: Bull
MASK DESCRIPTION: Raging Bull
GAMEPLAY: Gives the game a black-and-white filter
UNLOCK: Obtained by finding it in ‘The Metro’ (PS3/PS4/Vita Only)