Games like Formilion
Games like Formilion include Hotline Miami, Hotline Miami 2: Wrong Number, Post Void, Katana ZERO, and Ape Out. We matched them by the tags players give Formilion on Steam (Action, Top-Down, Violent, Pixel Graphics, and Difficult): closest matches first, and among equally close ones the better-known games.

Hotline Miami
Shared: Action · Violent · Top-Down

Hotline Miami 2: Wrong Number
Shared: Action · Violent · Pixel Graphics

Post Void
Shared: Difficult · Shooter · Action

Katana ZERO
Shared: Action · Pixel Graphics · Violent

Ape Out
Shared: Violent · Top-Down · Action

DOOM Eternal
Shared: Action · Violent · Shooter

12 is Better Than 6
Shared: Action · Shooter · Top-Down Shooter

Intravenous
Shared: Difficult · Top-Down · Action

Devil Daggers
Shared: Action · Difficult · Fast-Paced

Turbo Overkill
Shared: Action · Shooter · Retro

UBERMOSH Vol.5
Shared: Action · Pixel Graphics · Retro

Ghostrunner
Shared: Action · Difficult · Fast-Paced

RUINER
Shared: Action · Violent · Top-Down Shooter

Nuclear Throne
Shared: Pixel Graphics · Action · Difficult

Blasphemous
Shared: Pixel Graphics · Violent · Action

64.0
Shared: Action · Difficult · Retro

SANABI
Shared: Action · Pixel Graphics · Singleplayer

Party Hard
Shared: Pixel Graphics · Violent · Action

Super Meat Boy
Shared: Difficult · Pixel Graphics · Singleplayer

My Friend Pedro
Shared: Action · Shooter · Violent

Titan Souls
Shared: Pixel Graphics · Action · Difficult

Warhammer 40,000: Boltgun
Shared: Action · Pixel Graphics · Retro

Broforce
Shared: Action · Pixel Graphics · Shooter

Skul: The Hero Slayer
Shared: Action · Pixel Graphics · Difficult