Games like Kaiju
Games like Kaiju include AudioSurf, Chill with You : Lo-Fi Story, A Dance of Fire and Ice, LYNE, and Nodebuster. We matched them by the tags players give Kaiju on Steam (Rhythm, Idler, Music-Based Procedural Generation, Procedural Generation, and Atmospheric): closest matches first, and among equally close ones the better-known games.

AudioSurf
Shared: Rhythm · Music-Based Procedural Generation · Colorful

Chill with You : Lo-Fi Story
Shared: Relaxing · Atmospheric · Idler

A Dance of Fire and Ice
Shared: Rhythm · Colorful · Atmospheric

LYNE
Shared: Relaxing · Procedural Generation · Minimalist

Nodebuster
Shared: Idler · Relaxing · Casual

Cast n Chill
Shared: Idler · Relaxing · Atmospheric

Beat Hazard
Shared: Rhythm · Music-Based Procedural Generation · Space

Monument Valley 3
Shared: Relaxing · Atmospheric · Colorful

A Game About Feeding A Black Hole
Shared: Idler · Relaxing · Casual

Beat Hazard 2
Shared: Rhythm · Music-Based Procedural Generation · Procedural Generation

Digseum
Shared: Idler · Relaxing · Minimalist

Melody's Escape
Shared: Rhythm · Music-Based Procedural Generation · Colorful

No Man's Sky
Shared: Procedural Generation · Sci-fi · Space

Incredibox
Shared: Rhythm · Music-Based Procedural Generation · Relaxing

ISLANDERS
Shared: Relaxing · Atmospheric · Minimalist

Hook
Shared: Relaxing · Abstract · Minimalist

Melatonin
Shared: Rhythm · Relaxing · Colorful

Manifold Garden
Shared: Abstract · Atmospheric · Surreal

SpaceEngine
Shared: Sci-fi · Space · Casual

Superflight
Shared: Procedural Generation · Relaxing · Atmospheric

Cozy Grove
Shared: Relaxing · Atmospheric · Procedural Generation

ABZU
Shared: Atmospheric · Relaxing · Colorful

Terra Nil
Shared: Relaxing · Procedural Generation · Atmospheric

Shelldiver
Shared: Idler · Relaxing · Casual