Games like Milthm
Games like Milthm include Muse Dash, DJMAX RESPECT V, A Dance of Fire and Ice, MUSYNX, and Brawlhalla. We matched them by the tags players give Milthm on Steam (Rhythm, Casual, Anime, 2D Platformer, and Post-apocalyptic): closest matches first, and among equally close ones the better-known games.

Muse Dash
Shared: Rhythm · Anime · Casual

DJMAX RESPECT V
Shared: Rhythm · Casual · Anime

A Dance of Fire and Ice
Shared: Rhythm · Music · Casual

MUSYNX
Shared: Anime · Casual · Rhythm

Brawlhalla
Shared: Free to Play · Casual · 2D Platformer

Rhythm Doctor
Shared: Rhythm · Music · Indie

Neon Beats
Shared: Rhythm · Free to Play · Music

Sixtar Gate: STARTRAIL
Shared: Casual · Rhythm · Anime

Spin Rhythm XD
Shared: Rhythm · Casual · Music

Beat Saber
Shared: Rhythm · Music · Singleplayer

KAMITSUBAKI CITY ENSEMBLE
Shared: Rhythm · Anime · Casual

AudioSurf
Shared: Rhythm · Casual · Music

Hatsune Miku: Project DIVA Mega Mix+
Shared: Rhythm · Anime · Music

EZ2ON REBOOT : R
Shared: Rhythm · Casual · Anime

Ratatan
Shared: Anime · Rhythm · 2D Platformer

Voices from the Sea
Shared: Anime · Casual · Free to Play

KALPA: Cosmic Symphony
Shared: Rhythm · Casual · Anime

VRChat
Shared: Anime · Free to Play · Casual

Audiosurf 2
Shared: Rhythm · Casual · Music

Intralism
Shared: Rhythm · Casual · Music

Dota Underlords
Shared: Casual · Free to Play · Fantasy

Idle Champions of the Forgotten Realms
Shared: Free to Play · Fantasy · Casual

Geometry Dash
Shared: Rhythm · Music · Singleplayer

Zenless Zone Zero
Shared: Anime · Free to Play · Post-apocalyptic