Games like Ailment
Games like Ailment include CARRION, Hotline Miami, Hotline Miami 2: Wrong Number, Blasphemous, and Broforce. We matched them by the tags players give Ailment on Steam (Action, Indie, Gore, Violent, and Adventure): closest matches first, and among equally close ones the better-known games.

CARRION
Shared: Gore · Action · Pixel Graphics

Hotline Miami
Shared: Action · Indie · Violent

Hotline Miami 2: Wrong Number
Shared: Gore · Action · Violent

Blasphemous
Shared: Gore · Pixel Graphics · Indie

Broforce
Shared: Action · Pixel Graphics · Indie

My Friend Pedro
Shared: Action · Indie · Gore

MO:Astray
Shared: Action · Indie · Adventure

DOOM Eternal
Shared: Action · Gore · Violent

People Playground
Shared: Gore · Violent · 2D

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

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

NOT A HERO
Shared: Action · Indie · Pixel Graphics

SANABI
Shared: Action · Pixel Graphics · Adventure

Kindergarten 2
Shared: Gore · Indie · Adventure

RUINER
Shared: Action · Indie · Violent

BUTCHER
Shared: Action · Indie · Gore

The Ascent
Shared: Action · Top-Down Shooter · Indie

Terraria
Shared: Pixel Graphics · Adventure · 2D

Katana ZERO
Shared: Action · Pixel Graphics · Indie

House
Shared: Gore · Action · Pixel Graphics

Prodeus
Shared: Action · Gore · Indie

Bright Memory: Infinite
Shared: Action · Indie · Gore

Serious Sam 4
Shared: Action · Gore · Violent

The Walking Dead: Saints & Sinners
Shared: Action · Gore · Adventure