Games like Castleborne Survivors
Games like Castleborne Survivors include Vampire Survivors, Death Must Die, Megabonk, Halls of Torment, and Soulstone Survivors. We matched them by the tags players give Castleborne Survivors on Steam (Action Roguelike, Bullet Heaven, 2D Platformer, Side Scroller, and Action): closest matches first, and among equally close ones the better-known games.

Vampire Survivors
Shared: Action Roguelike · Roguelite · Casual

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

Megabonk
Shared: Action Roguelike · Bullet Heaven · Roguelite

Halls of Torment
Shared: Action Roguelike · Roguelite · Action

Soulstone Survivors
Shared: Action Roguelike · Bullet Heaven · Roguelite

Skul: The Hero Slayer
Shared: Action Roguelike · Action · Roguelite

Rogue Legacy
Shared: Action Roguelike · Action · Metroidvania

Dead Cells
Shared: Action Roguelike · Metroidvania · Roguelike

Boneraiser Minions
Shared: Action Roguelike · Bullet Heaven · Roguelite

Anomaly Agent
Shared: Action Roguelike · 2D Platformer · Side Scroller

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

Rogue Legacy 2
Shared: Metroidvania · Action · Arcade

Hades
Shared: Action Roguelike · Roguelite · Action

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

Jotunnslayer: Hordes of Hel
Shared: Action Roguelike · Bullet Heaven · Roguelite

BALL x PIT
Shared: Action · Action Roguelike · Roguelite

Hades II
Shared: Action · Action Roguelike · Roguelite

Dungreed
Shared: Action Roguelike · Action · Roguelite

Brotato
Shared: Action Roguelike · Bullet Heaven · Roguelike

Nova Drift
Shared: Action Roguelike · Bullet Heaven · Roguelite

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

30XX
Shared: Action Roguelike · 2D Platformer · Side Scroller

Conquest Dark
Shared: Bullet Heaven · Action Roguelike · Action

Spirit Hunters: Infinite Horde
Shared: Action Roguelike · Bullet Heaven · Action