Single-player games like Ozone Guardian
Below are 9 single-player Steam games similar to Ozone Guardian, 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 Ozone Guardian page.
Ranked picks
- 1

Lost Galaxy: Survivors
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Casual with Ozone Guardian.
Defend massive interdimensional portals against relentless alien swarms in this fast-paced sci-fi top-down survival shooter.
- 2

GUN KING
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Indie with Ozone Guardian.
GUN KING is a fast-paced top-down arcade shooter with unique gun mods that lets you play your way. Unlock and equip powerful gun mods to create wild synergies, amp up your firepower, and blast through hordes of enemies.
- 3

Line Defense
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Indie with Ozone Guardian.
Move or die. Dodge, dash, and build powerful combos to survive relentless enemy waves in this fast-paced arena survival game. Play solo or in chaotic 4-player local co-op.
- 4

Last Star
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action with Ozone Guardian.
Last Star is a space shooter roguelite with tower defense elements. Pilot a spaceship to protect your solar core from endless waves of alien invaders. Upgrade both your core and spaceship to become unstoppable. Execute tactical counterattacks against alien motherships to slow down the invasion.
- 5

Orbit Breaker
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Casual with Ozone Guardian.
Choose a geometric core, survive escalating waves with automatic weapons, and evolve matching weapons and passives into stronger builds. Explore sectors, find unlocks, and defeat the boss.
- 6

Space War: Infinity
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Indie with Ozone Guardian.
Vertical semi-procedural shmup with upgrades, real-time enemy waves, and infinite replayability. Level up your ship, unlock 20+ weapons, defeat 5 bosses, and survive endless bullet-hell combat.
- 7

Larva Mortus
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Indie with Ozone Guardian.
Larva Mortus is a fast-paced hack and slash top-down shooter. As an agent specializing in exorcism, you are tasked to hunt monsters of the supernatural in a dark, ominous, and randomly generated atmosphere full of undead, terrifying and demonic nightmares.
- 8

Chippy
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Indie with Ozone Guardian.
Chip destructible bosses apart pixel-by-pixel in this twin-stick bullet-hell shooter.
- 9

Colossal Saga
Single-player alternative to Ozone Guardian — playable solo, no multiplayer required. Shares Action and Indie with Ozone Guardian.
Play with a variety of unique characters to conquer your friends or enemies in Versus, Survival and Dungeon mode, in this 1-4 players, couch coop action fighting game!