Games like SUFFER
Games like SUFFER include DOOM Eternal, Prodeus, HROT, Warhammer 40,000: Boltgun, and Turbo Overkill. We matched them by the tags players give SUFFER on Steam (Indie, Action, Gore, Violent, and FPS): closest matches first, and among equally close ones the better-known games.

DOOM Eternal
Shared: Gore · Action · FPS

Prodeus
Shared: Gore · Action · FPS

HROT
Shared: FPS · Indie · Retro

Warhammer 40,000: Boltgun
Shared: FPS · Action · Retro

Turbo Overkill
Shared: Action · FPS · Indie

ULTRAKILL
Shared: Gore · FPS · Boomer Shooter

Trepang2
Shared: Gore · FPS · Shooter

DOOM
Shared: Action · Gore · FPS

Maximum Action
Shared: Action · Gore · Indie

CULTIC
Shared: Action · FPS · Shooter

DUSK
Shared: FPS · Retro · Boomer Shooter

Bright Memory: Infinite
Shared: Action · Indie · FPS

Hotline Miami
Shared: Action · Indie · Violent

Forgive Me Father
Shared: Action · FPS · Indie

DOOM 64
Shared: Action · FPS · Gore

Wolfenstein II: The New Colossus
Shared: Action · Gore · FPS

Counter-Strike 2
Shared: FPS · Action · Shooter

Call of Duty®
Shared: FPS · Action · Shooter

Serious Sam 4
Shared: Action · Gore · FPS

Serious Sam Fusion 2017 (beta)
Shared: Action · Gore · Indie

GoreBox
Shared: Gore · Violent · FPS

DOOM + DOOM II
Shared: Action · FPS · Retro

Ready or Not
Shared: FPS · Shooter · Action

Hellbound
Shared: Indie · Action · Gore