Games like Thor's Ascension: Nine Realms
Games like Thor's Ascension: Nine Realms include Hades, Hades II, Skul: The Hero Slayer, Black Myth: Wukong, and Megabonk. We matched them by the tags players give Thor's Ascension: Nine Realms on Steam (Action, Action Roguelike, Roguelike, 3D, and Realistic): closest matches first, and among equally close ones the better-known games.

Hades
Shared: Action Roguelike · Action · Roguelike

Hades II
Shared: Action · Roguelike · Action Roguelike

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

Black Myth: Wukong
Shared: Action · Mythology · 3D

Megabonk
Shared: Action Roguelike · Roguelike · Action

Dead Cells
Shared: Roguelike · Action Roguelike · Adventure

God of War
Shared: Action · Mythology · Adventure

Ravenswatch
Shared: Roguelike · Action Roguelike · Action

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

God of War Ragnarök
Shared: Action · Mythology · Adventure

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

Cinderia
Shared: Action Roguelike · Action · Roguelike

Children of Morta
Shared: Roguelike · Action Roguelike · Hack and Slash

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

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

Crab Champions
Shared: Action Roguelike · Roguelike · 3D

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

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

Red Dead Redemption 2
Shared: Action · Realistic · Adventure

Wizard of Legend
Shared: Action Roguelike · Roguelike · Action

Soulstone Survivors
Shared: Action Roguelike · Roguelike · Action

Death Must Die
Shared: Action Roguelike · Action · Roguelike

Wolcen: Lords of Mayhem
Shared: Action · Isometric · Hack and Slash

Rogue Legacy
Shared: Roguelike · Action Roguelike · Action