Games like Summertime Madness
Games like Summertime Madness include Viewfinder, Manifold Garden, Antichamber, Outer Wilds, and Creaks. We matched them by the tags players give Summertime Madness on Steam (Surreal, Puzzle, Exploration, Puzzle Platformer, and Atmospheric): closest matches first, and among equally close ones the better-known games.

Viewfinder
Shared: Puzzle · Puzzle Platformer · Surreal

Manifold Garden
Shared: Surreal · Puzzle · Exploration

Antichamber
Shared: Puzzle · Surreal · Exploration

Outer Wilds
Shared: Exploration · Puzzle · Story Rich

Creaks
Shared: Puzzle · Surreal · Atmospheric

The Witness
Shared: Puzzle · Exploration · First-Person

Superliminal
Shared: Puzzle · Surreal · First-Person

What Remains of Edith Finch
Shared: Atmospheric · Story Rich · Exploration

Portal 2
Shared: Puzzle · Puzzle Platformer · First-Person

Firewatch
Shared: Atmospheric · Story Rich · Exploration

NaissanceE
Shared: Exploration · Atmospheric · Surreal

Blue Prince
Shared: Puzzle · Exploration · Story Rich

Chants of Sennaar
Shared: Puzzle · Atmospheric · Exploration

The Unfinished Swan
Shared: Puzzle · Exploration · Surreal

Amnesia: Rebirth
Shared: Puzzle · Action-Adventure · First-Person

COCOON
Shared: Puzzle · Exploration · Puzzle Platformer

ANIMAL WELL
Shared: Puzzle · Exploration · Puzzle Platformer

The Talos Principle
Shared: Puzzle · Atmospheric · First-Person

GRIS
Shared: Atmospheric · Hand-drawn · Puzzle

FAR: Lone Sails
Shared: Atmospheric · Exploration · Puzzle

Obduction
Shared: Puzzle · Exploration · Surreal

Kairo
Shared: Puzzle · Exploration · Surreal

Call of the Sea
Shared: Puzzle · Story Rich · First-Person

The Talos Principle 2
Shared: Puzzle · Story Rich · Puzzle Platformer