Single-player games like Diluvian Ultra
Below are 9 single-player Steam games similar to Diluvian Ultra, ranked by player overlap. Every pick carries Steam's Single-player category, so multiplayer-only titles or always-online games don't sneak in. imho.run pulls the category data from Steam directly — Single-player here matches what the store labels.
Want the full alternatives list (paid + free + Steam Deck + cheaper picks)? See the parent games like Diluvian Ultra page.
Ranked picks
- 1

Diluvian Ultra: Awakening
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action with Diluvian Ultra.
Diluvian Ultra: Awakening shows a never-before seen part of Diluvian Ultra's story, preceding the events of the main game. As a young Diluvian Knight, stage a heroic defense against insurmountable odds, in this single-player FPS with a retro aesthetic and fast-paced, strategic combat.
- 2

Pile 'Em High Episode 3: Convalescence
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
Deep in Colorado’s Rocky Mountains, a secluded estate becomes ground zero for terror. Pile ’Em High 3 throws you into nonstop action‑horror mayhem—cultists, zombies, abominations—all standing between you and the truth behind the world‑shattering Pandemic
- 3

Beyond Citadel
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
Beyond Citadel is an anime style retro throwback shooter inspired by the classics of the 90's, with realistic gunplay mechanics, anime violence and fast paced combat. Fight your way through the heavily armed mechanical fortress and discover the secret that lies beneath.
- 4

MULLET MADJACK
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
MULLET MADJACK is a HIGH-OCTANE-ACTION SHOOTER that put you directly inside a CLASSIC ANIME. Pick your favorite weapon and reach the last floor; Beat your best time or try again. Haste makes waste… OF YOUR ENEMIES!
- 5

Relentless Frontier
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
Relentless Frontier is a fast paced sci-fi FPS running on the GZDoom Engine, with a strong focus on mobility, strategy, and exploration. Use your Omnistruct to replicate new weapons and abilities to help you traverse the terrain and demolish threats, while escaping from Ross 128-b in one piece.
- 6

Project Warlock II
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
Adrenaline-pumping gore retro funhouse that’s full of guns, magic, demons, vertical arenas, 3D visuals, 2D sprites, and heavy metal music. Inspired by FPS classics like Quake and Doom 64, Project Warlock II is the explosive boomer shooter sequel you were too shy to ask for.
- 7

Blake Stone: Aliens of Gold
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action with Diluvian Ultra.
Wolfenstein 3D took you into the past, thrusting you into a world at war. Blake rockets you into the future where a sinister madman, using genetics to create an army of bizarre creatures, is waging war on Earth. Blake has more of everything!
- 8

Beyond Sunset
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
Cyberpunk first-person shooter with a rich story and RPG elements. You are Lucy, an enhanced street samurai searching for lost memories. Fight in large, open, interactive levels overtaken by yakuza, zombies, robots and bosses!
- 9

Viscerafest
Single-player alternative to Diluvian Ultra — playable solo, no multiplayer required. Shares Action and Indie with Diluvian Ultra.
Viscerafest is a Sci-Fi Fantasy Singleplayer Arena FPS with minor Collectathon elements. Fight through hordes of aliens and eldritch monstrosities wielding a slew of powerful weapons, juggling your resources, and exploring over 23 intricately designed hand-crafted levels.