Games like Rift Horizon
Games like Rift Horizon include Halls of Torment, Megabonk, Hades II, Hades, and Soulstone Survivors. We matched them by the tags players give Rift Horizon on Steam (Action, Action RPG, Arcade, Roguelike, and Action Roguelike): closest matches first, and among equally close ones the better-known games.

Halls of Torment
Shared: Action Roguelike · Action RPG · Roguelite

Megabonk
Shared: Roguelike · Action Roguelike · Action

Hades II
Shared: Action · Roguelike · Roguelite

Hades
Shared: Action Roguelike · Action · Roguelite

Soulstone Survivors
Shared: Action RPG · Action Roguelike · Roguelike

BALL x PIT
Shared: Action · Arcade · Roguelike

Vampire Survivors
Shared: Action Roguelike · Roguelite · Roguelike

Yet Another Zombie Survivors
Shared: Action Roguelike · Arcade · Action RPG

Nova Drift
Shared: Arcade · Action RPG · Action Roguelike

Hero Siege
Shared: Action RPG · Action Roguelike · Roguelike

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

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

Death Must Die
Shared: Action Roguelike · Action · Roguelite

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

Cinderia
Shared: Action · Action Roguelike · Roguelike

Heroes of Hammerwatch II
Shared: Action RPG · Action · Action Roguelike

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

Ravenswatch
Shared: Roguelike · Action · Action Roguelike

The Spell Brigade
Shared: Roguelite · Action Roguelike · Roguelike

Shape of Dreams
Shared: Action Roguelike · Action · Roguelite

WARRIORS: Abyss
Shared: Action · Action RPG · Action Roguelike

Jotunnslayer: Hordes of Hel
Shared: Action Roguelike · Action RPG · Roguelike

Dead Cells
Shared: Roguelike · Action Roguelike · Roguelite

Crab Champions
Shared: Action Roguelike · Roguelike · Arcade