Games like Californium
Games like Californium include Slime Rancher, Antichamber, Manifold Garden, Morphopolis, and Chants of Sennaar. We matched them by the tags players give Californium on Steam (Psychedelic, Sci-fi, Experimental, Colorful, and Point & Click): closest matches first, and among equally close ones the better-known games.

Slime Rancher
Shared: Exploration · Colorful · Adventure

Antichamber
Shared: Surreal · Exploration · Indie

Manifold Garden
Shared: Psychedelic · Surreal · Experimental

Morphopolis
Shared: Point & Click · Psychedelic · Colorful

Chants of Sennaar
Shared: Colorful · Point & Click · Adventure

Hylics
Shared: Psychedelic · Surreal · Indie

Samorost 1
Shared: Point & Click · Surreal · Psychedelic

Moncage
Shared: Surreal · Experimental · Adventure

No Man's Sky
Shared: Sci-fi · Exploration · Adventure

The Witness
Shared: Colorful · Exploration · First-Person

Road 96
Shared: Colorful · Adventure · First-Person

Hyperbolica
Shared: Surreal · Sci-fi · Psychedelic

Arctic Eggs
Shared: Sci-fi · Surreal · Exploration

Umurangi Generation
Shared: Indie · Experimental · Sci-fi

Happy Game
Shared: Psychedelic · Surreal · Indie

In Other Waters
Shared: Exploration · Adventure · Point & Click

The Room
Shared: Point & Click · Adventure · Indie

The Artful Escape
Shared: Psychedelic · Sci-fi · Adventure

Firewatch
Shared: Adventure · Exploration · First-Person

Endacopia
Shared: Point & Click · Surreal · Adventure

Outer Wilds
Shared: Exploration · Adventure · Sci-fi

BABBDI
Shared: Exploration · Surreal · Casual

Kentucky Route Zero: PC Edition
Shared: Point & Click · Surreal · Adventure

Superliminal
Shared: Surreal · Psychedelic · First-Person