Games like Infinite Abyss
Games like Infinite Abyss include Natural Selection 2, Heat Signature, Space Pirates And Zombies 2, FTL: Faster Than Light, and Aliens: Dark Descent. We matched them by the tags players give Infinite Abyss on Steam (Action, Indie, Strategy, Aliens, and Space): closest matches first, and among equally close ones the better-known games.

Natural Selection 2
Shared: Strategy · Action · Indie

Heat Signature
Shared: Indie · Space · Action

Space Pirates And Zombies 2
Shared: Action · Strategy · Indie

FTL: Faster Than Light
Shared: Strategy · Indie · Space

Aliens: Dark Descent
Shared: Action · Strategy · Aliens

Space Pirates and Zombies
Shared: Action · Indie · Space

X-Morph: Defense
Shared: Action · Strategy · Indie

Reassembly
Shared: Strategy · Space · Action

Infested Planet
Shared: Action · Strategy · Indie

Between the Stars
Shared: Action · Space · Indie

Iron Marines
Shared: Strategy · Action · Indie

Defense Grid: The Awakening
Shared: Strategy · Indie · Aliens

Space Run
Shared: Strategy · Indie · Space

Mount & Blade II: Bannerlord
Shared: Strategy · Action · Indie

Freeman: Guerrilla Warfare
Shared: Action · Strategy · Indie

Orcs Must Die! 2
Shared: Action · Strategy · Indie

Total Tank Simulator
Shared: Action · Strategy · Indie

House of the Dying Sun
Shared: Action · Indie · Space

Deliver Us The Moon
Shared: Indie · Action · Space

Sanctum 2
Shared: Action · Strategy · Indie

ENDLESS Space™ 2
Shared: Strategy · Space · Action

Space Crew: Legendary Edition
Shared: Action · Strategy · Indie

Starship Troopers: Extermination
Shared: Action · Aliens · Indie

Orcs Must Die!
Shared: Action · Strategy · Indie