Single-player games like Diffusion
Below are 8 single-player Steam games similar to Diffusion, 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 Diffusion page.
Ranked picks
- 1
Axom: Conquest
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy and Indie with Diffusion.
Build and defend your fortress while expanding out in this hold-out tower defense roguelite. Battle across a procedural alien homeworld, fight back corrupted terrain, discover hundreds of structures and upgrades as physics-driven swarms threaten to wipe out humanity.
- 2
Hexfall: Planetary Defense
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy and Indie with Diffusion.
Hexfall is a planet-scale tower defense game where over 100,000 enemies attack at once. Mine the crust, wire the power and arm a hex world against an armada that fills the sky long before it comes down.
- 3
Ironfront Express
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy with Diffusion.
Upgrade your engine’s arsenal in this bullet hell, tower defense roguelite featuring the most heavily armored locomotive in existence. Engineer and command the Ironfront Express in a unique take on lane defense where you upgrade with specialized turrets, drones, and tactical abilities.
- 4
Astro Company
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy with Diffusion.
Build the path. Defend the Core. Combine towers, cards, and artifacts into broken synergies in an endless tower defense roguelike.
- 5
Von Neumann Project
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy and Indie with Diffusion.
Von Neumann Project is a space based RTS where you build, mine, and expand across the universe in an attempt to find your creator's equals. Play across 4 different sectors with 28 handcrafted missions, with each sector introducing unique enemies, buildings, and missions.
- 6
Anx Defense
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy and Indie with Diffusion.
Defend your Nexus by placing mirrors and buildings on the path of your projectiles. Deflect, empower, manage and solve each map using your creative and strategic mind.
- 7
Micron Defense Force
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy with Diffusion.
A Roguelike Tower Defense in space with missions to conquer. Can you hold against the spreading alien bosses? Build and upgrade towers against the corruption. Choose your technologies and warpspeed your way to victory.
- 8
Endless Defense
Single-player alternative to Diffusion — playable solo, no multiplayer required. Shares Strategy and Indie with Diffusion.
Endless Defense is a roguelite sci-fi tower defense game where every run becomes a new build. Place turrets, choose traits, draw upgrade cards, use special tiles, and evolve your defense to survive endless waves of enemies, elites, and bosses.