Games like Cast Out Colony
Games like Cast Out Colony include Time Wasters, Megabonk, Nova Drift, Deep Rock Galactic: Survivor, and 20 Minutes Till Dawn. We matched them by the tags players give Cast Out Colony on Steam (Bullet Heaven, Action Roguelike, Arena Shooter, Shoot 'Em Up, and Twin Stick Shooter): closest matches first, and among equally close ones the better-known games.

Time Wasters
Shared: Bullet Heaven · Action Roguelike · Twin Stick Shooter

Megabonk
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Nova Drift
Shared: Shoot 'Em Up · Action Roguelike · Bullet Hell

Deep Rock Galactic: Survivor
Shared: Action Roguelike · Bullet Heaven · Bullet Hell

20 Minutes Till Dawn
Shared: Action Roguelike · Bullet Hell · Shoot 'Em Up

Brotato
Shared: Action Roguelike · Bullet Heaven · Bullet Hell

Soulstone Survivors
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Rogue: Genesia
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Nordic Ashes: Survivors of Ragnarok
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Death Must Die
Shared: Action Roguelike · Bullet Heaven · Bullet Hell

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Roguelite

BALL x PIT
Shared: Action Roguelike · Bullet Hell · Roguelite

Halls of Torment
Shared: Action Roguelike · Bullet Hell · Roguelite

The Spell Brigade
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Arms of God
Shared: Bullet Heaven · Action Roguelike · Arena Shooter

Yet Another Zombie Survivors
Shared: Bullet Heaven · Action Roguelike · Roguelite

Tower of Babel: Survivors of Chaos
Shared: Bullet Heaven · Action Roguelike · Bullet Hell

Vital Shell
Shared: Action Roguelike · Bullet Heaven · Arena Shooter

God Of Weapons
Shared: Action Roguelike · Arena Shooter · Bullet Hell

Pesticide Not Required
Shared: Action Roguelike · Shoot 'Em Up · Bullet Hell

Temtem: Swarm
Shared: Bullet Heaven · Action Roguelike · Twin Stick Shooter

Boneraiser Minions
Shared: Action Roguelike · Bullet Hell · Bullet Heaven

X Invader
Shared: Action Roguelike · Arena Shooter · Shoot 'Em Up

Enter the Gungeon
Shared: Action Roguelike · Bullet Hell · Twin Stick Shooter