Games like Strings Theory
Games like Strings Theory include LIMBO, INSIDE, Little Nightmares, Portal 2, and FEZ. We matched them by the tags players give Strings Theory on Steam (Indie, Puzzle Platformer, Platformer, Singleplayer, and Adventure): closest matches first, and among equally close ones the better-known games.

LIMBO
Shared: Indie · Puzzle Platformer · Platformer

INSIDE
Shared: Puzzle Platformer · Indie · 2.5D

Little Nightmares
Shared: Puzzle Platformer · Singleplayer · Adventure

Portal 2
Shared: Platformer · Singleplayer · Puzzle Platformer

FEZ
Shared: Indie · Platformer · Singleplayer

Never Alone (Kisima Ingitchuna)
Shared: Indie · Platformer · Adventure

Trine 2: Complete Story
Shared: Puzzle Platformer · Platformer · Co-op

FAR: Lone Sails
Shared: Adventure · Singleplayer · Indie

Pikuniku
Shared: Indie · Adventure · Casual

Chained Together
Shared: Platformer · Adventure · Puzzle Platformer

Seen
Shared: Indie · Singleplayer · Adventure

GRIS
Shared: Indie · Adventure · Platformer

Little Nightmares II
Shared: Singleplayer · Adventure · Puzzle

Human Fall Flat
Shared: Co-op · Puzzle Platformer · Adventure

CATO: Buttered Cat
Shared: Puzzle Platformer · Indie · Adventure

Planet of Lana
Shared: Puzzle Platformer · Singleplayer · Platformer

Nihilumbra
Shared: Indie · Platformer · Adventure

The Last Campfire
Shared: Indie · Singleplayer · Adventure

The Cave
Shared: Platformer · Adventure · Indie

Defy Gravity Extended
Shared: Puzzle Platformer · Indie · Platformer

Pinstripe
Shared: Indie · Adventure · Puzzle Platformer

PICO PARK
Shared: Puzzle Platformer · Co-op · Casual

Moncage
Shared: Indie · Singleplayer · Casual

Viewfinder
Shared: Puzzle Platformer · Singleplayer · Puzzle