Games like Harmoni
Games like Harmoni include Beat Saber, A Dance of Fire and Ice, DJMAX RESPECT V, Geometry Dash, and Halo Infinite. We matched them by the tags players give Harmoni on Steam (Action, Rhythm, 2D, Moddable, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Beat Saber
Shared: Rhythm · Moddable · Singleplayer

A Dance of Fire and Ice
Shared: Rhythm · Singleplayer · 2D

DJMAX RESPECT V
Shared: Rhythm · Action · 2D

Geometry Dash
Shared: 2D · Rhythm · Singleplayer

Halo Infinite
Shared: Action · Free to Play · Singleplayer

Rhythm Doctor
Shared: Rhythm · Action · Singleplayer

People Playground
Shared: Moddable · 2D · Singleplayer

Warframe
Shared: Action · Free to Play · Singleplayer

Neon Beats
Shared: Rhythm · Free to Play · 2D

Just Shapes & Beats
Shared: Rhythm · 2D · Action

Hi-Fi RUSH
Shared: Action · Rhythm · Singleplayer

Delta Force
Shared: Free to Play · Action · Singleplayer

Muse Dash
Shared: Rhythm · 2D · Singleplayer

War Thunder
Shared: Action · Free to Play · Free To Play

Call of Duty®: Warzone™
Shared: Action · Free to Play · Singleplayer

Fallout: New Vegas
Shared: Moddable · Singleplayer · Action

Grand Theft Auto IV: The Complete Edition
Shared: Action · Singleplayer · Moddable

Endless Sky
Shared: Free to Play · Singleplayer · 2D

Battlefield™ REDSEC
Shared: Action · Free to Play · Singleplayer

Skul: The Hero Slayer
Shared: Action · 2D · Singleplayer

Melody's Escape
Shared: Rhythm · Moddable · Action

Melatonin
Shared: Rhythm · 2D · Action

One Finger Death Punch
Shared: Action · Singleplayer · 2D

Ultimate Custom Night
Shared: Free to Play · Singleplayer · Action