Games like Nightmare Reaper
Games like Nightmare Reaper include Warhammer 40,000: Boltgun, CULTIC, DUSK, HROT, and Ion Fury. We matched them by the tags players give Nightmare Reaper on Steam (Boomer Shooter, FPS, Retro, Looter Shooter, and Roguelite): closest matches first, and among equally close ones the better-known games.

Warhammer 40,000: Boltgun
Shared: Boomer Shooter · FPS · Retro

CULTIC
Shared: Boomer Shooter · FPS · Shooter

DUSK
Shared: Boomer Shooter · FPS · Retro

HROT
Shared: FPS · Boomer Shooter · Retro

Ion Fury
Shared: Boomer Shooter · FPS · Retro

Prodeus
Shared: Boomer Shooter · FPS · Retro

Selaco
Shared: FPS · Boomer Shooter · Shooter

Turbo Overkill
Shared: Boomer Shooter · FPS · Retro

DOOM + DOOM II
Shared: FPS · Retro · Boomer Shooter

Borderlands 2
Shared: FPS · Shooter · Loot

DOOM 64
Shared: FPS · Retro · Boomer Shooter

WRATH: Aeon of Ruin
Shared: Boomer Shooter · FPS · Retro

SharpShooter3D
Shared: Boomer Shooter · FPS · Shooter

Gunfire Reborn
Shared: FPS · Roguelite · Looter Shooter

Forgive Me Father
Shared: Boomer Shooter · FPS · Retro

Project Warlock
Shared: Boomer Shooter · FPS · Retro

Borderlands 3
Shared: FPS · Looter Shooter · Loot

MOUSE: P.I. For Hire
Shared: FPS · Boomer Shooter · First-Person

Trepang2
Shared: FPS · Shooter · Violent

STRAFE: Gold Edition
Shared: Roguelite · FPS · Retro

Quake
Shared: FPS · Shooter · Boomer Shooter

Call of Duty®
Shared: FPS · Shooter · First-Person

ULTRAKILL
Shared: FPS · Boomer Shooter · Retro

The Citadel
Shared: FPS · Retro · Violent