Games like Diary of Defender
Games like Diary of Defender include Hard Bullet, Blade and Sorcery, GORN, Hotline Miami, and The Walking Dead: Saints & Sinners. We matched them by the tags players give Diary of Defender on Steam (Gore, Violent, Action, Adventure, and Indie): closest matches first, and among equally close ones the better-known games.

Hard Bullet
Shared: Action · Violent · VR

Blade and Sorcery
Shared: Gore · VR · Action

GORN
Shared: Gore · Action · Violent

Hotline Miami
Shared: Violent · Action · Gore

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

DOKA 2 KISHKI EDITION
Shared: Gore · Violent · Action

Blood Trail
Shared: Gore · Violent · Action

CARRION
Shared: Gore · Action · Violent

People Playground
Shared: Gore · Violent · Simulation

SURV1V3
Shared: Action · Adventure · VR

Paint the Town Red
Shared: Gore · Violent · Action

DOOM Eternal
Shared: Gore · Action · Violent

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

Vertigo Remastered
Shared: Action · Gore · Adventure

Survival Zombies The Inverted Evolution
Shared: Action · Adventure · Gore

My Friend Pedro
Shared: Action · Gore · Indie

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

Serious Sam 4
Shared: Gore · Action · Violent

Hellblade: Senua's Sacrifice VR Edition
Shared: Action · Violent · Adventure

Ultimate Epic Battle Simulator
Shared: Action · Simulation · Violent

BONEWORKS
Shared: Action · VR · Adventure

G2 Fighter / 基因特工
Shared: Action · Adventure · Indie

Contractors
Shared: Violent · Action · VR

The Walking Dead Onslaught
Shared: Action · Gore · Adventure