Single-player games like Gray Goo
Below are 8 single-player Steam games similar to Gray Goo, 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 Gray Goo page.
Ranked picks
- 1
Wayfarer Colony: Veylan
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Casual with Gray Goo.
Explore the uncharted Veylan star system as Kael, a Wayfarers pilot searching for a new home for humanity. Battle the rival Vesper Accord, survive hostile environments across diverse planets and moons, and uncover the story through 30 missions featuring retro-inspired gameplay and visuals.
- 2
Gravitaws
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Indie with Gray Goo.
Gravitaws is a retro-style stage shooter inspired by Jaws (NES). Explore a dynamic overworld map. Collect research materials and upgrades, while evading an Alien invader. The story is delivered in classic style cutscenes. Fight bosses, survive, collect, fish, and bomb your way to victory.
- 3
Throst
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Indie with Gray Goo.
Throst is a 2D-retro-arcade-action adventure about precision flying under constant gravity. Dive through tight tunnels, outmaneuver and destroy defenses. Grab the enemy’s energy orbs, and blast your way back to orbit before you’re crushed or shot down.
- 4
UfoPilot : The Phadt Menace - Steam Edition
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Indie with Gray Goo.
A sci-fi retro side-scrolling shoot-em-up / rescue game.
- 5
FORTRESS DEFENDER
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Indie with Gray Goo.
This game, "FORTRESS DEFENDER", is a side-scrolling power-up shooting game with an 80's flavor. Defeat the enemies that appear one after another, dodge their attacks, and aim for the boss that lurks in the depths of the stage. There are a total of eight stages with various tricks and bosses.
- 6
Chromacell
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action with Gray Goo.
In this sideways scrolling shmup, take control of your spaceship and navigate through vibrant pixelated environments filled with hordes of enemy spacecraft. Upgrade your ship and weapons, dodge enemy fire while blasting through each stage. Emerge victorious as the ultimate space pilot!
- 7
MoonLess
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Indie with Gray Goo.
Moonless is a challenging side-scrolling platformer in the style of classic arcade games of the 1980s, where you control a helpless astronaut who has been left stranded on the moon, and now has to face an invading alien force to earn a chance to go home.
- 8
PigShip and the Giant Wolf
Single-player alternative to Gray Goo — playable solo, no multiplayer required. Shares Action and Indie with Gray Goo.
Pig Ship and the Giant Wolf is a classic Shoot'em Up with a 8btis monochrome aesthetic. Cross the 6 worlds full of enemies and defeat the Giant Wolf to save your brothers.