Games like Castle Selbst
Games like Castle Selbst include Black Myth: Wukong, CrossCode, Halls of Torment, Vampire Survivors, and Hero Siege. We matched them by the tags players give Castle Selbst on Steam (RPG, Bullet Hell, Puzzle, PvE, and Action RPG): closest matches first, and among equally close ones the better-known games.

Black Myth: Wukong
Shared: RPG · Action RPG · Action

CrossCode
Shared: RPG · Action RPG · Puzzle

Halls of Torment
Shared: Bullet Hell · RPG · Action RPG

Vampire Survivors
Shared: Bullet Hell · 2D · Pixel Graphics

Hero Siege
Shared: RPG · Action RPG · Pixel Graphics

Death Must Die
Shared: Bullet Hell · RPG · Pixel Graphics

DELTARUNE
Shared: RPG · Bullet Hell · Pixel Graphics

Archvale
Shared: Bullet Hell · Action · Action RPG

The Mageseeker: A League of Legends Story™
Shared: RPG · 2D · Pixel Graphics

Warframe
Shared: RPG · Action RPG · Action

Last Epoch
Shared: RPG · Action RPG · Top-Down

Dragon's Dogma 2
Shared: RPG · Action RPG · Action

STAR OCEAN THE SECOND STORY R
Shared: RPG · Action RPG · PvE

Hogwarts Legacy
Shared: RPG · Magic · Singleplayer

Turnip Boy Commits Tax Evasion
Shared: RPG · Puzzle · Top-Down

Drova - Forsaken Kin
Shared: RPG · Action RPG · 2D

MONSTER HUNTER RISE
Shared: RPG · Action · Action RPG

Eastward
Shared: RPG · Action RPG · Pixel Graphics

The Slormancer
Shared: RPG · Action RPG · 2D

Torchlight: Infinite
Shared: RPG · Action RPG · Action

UNDECEMBER: The Farside
Shared: RPG · Action RPG · Action

Wolcen: Lords of Mayhem
Shared: RPG · Action RPG · Action

The Escapists
Shared: 2D · Pixel Graphics · Action

FINAL FANTASY VII REMAKE INTERGRADE
Shared: RPG · Action RPG · Action