Games like GetsuFumaDen: Undying Moon
Games like GetsuFumaDen: Undying Moon include Hades, The Binding of Isaac: Rebirth, Hades II, Dead Cells, and The Binding of Isaac. We matched them by the tags players give GetsuFumaDen: Undying Moon on Steam (Roguelike, Hack and Slash, Atmospheric, Difficult, and Action Roguelike): closest matches first, and among equally close ones the better-known games.

Hades
Shared: Hack and Slash · Action Roguelike · Roguelike

The Binding of Isaac: Rebirth
Shared: Roguelike · Action Roguelike · Difficult

Hades II
Shared: Roguelike · Hack and Slash · Action Roguelike

Dead Cells
Shared: Roguelike · Action Roguelike · Hack and Slash

The Binding of Isaac
Shared: Roguelike · Action Roguelike · Difficult

Ravenswatch
Shared: Roguelike · Action Roguelike · Difficult

Astral Ascent
Shared: Hack and Slash · Action Roguelike · Atmospheric

Cinderia
Shared: Hack and Slash · Roguelike · Action Roguelike

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

Garden of Witches
Shared: Roguelike · Action Roguelike · Hack and Slash

Windblown
Shared: Hack and Slash · Action Roguelike · Dark Fantasy

Halls of Torment
Shared: Action Roguelike · Roguelike · Dark Fantasy

Risk of Rain 2
Shared: Roguelike · Action Roguelike · Action

Brotato
Shared: Roguelike · Action Roguelike · Hack and Slash

Soulstone Survivors
Shared: Action Roguelike · Roguelike · Hack and Slash

Death Must Die
Shared: Action Roguelike · Hack and Slash · Roguelike

Megabonk
Shared: Roguelike · Action Roguelike · Roguelite

Jotunnslayer: Hordes of Hel
Shared: Hack and Slash · Action Roguelike · Roguelike

Curse of the Dead Gods
Shared: Action Roguelike · Roguelike · Difficult

Black Myth: Wukong
Shared: Action · Atmospheric · Dark Fantasy

Spelunky
Shared: Roguelike · Action Roguelike · Difficult

Nuclear Throne
Shared: Roguelike · Action Roguelike · Difficult

Enter the Gungeon
Shared: Roguelike · Action Roguelike · Difficult

SWORN
Shared: Hack and Slash · Action Roguelike · Roguelike