Games like Not Sure About That
Games like Not Sure About That include Chained Together, Portal 2, FEZ, Refunct, and Supraland. We matched them by the tags players give Not Sure About That on Steam (Trivia, Platformer, Adventure, Casual, and Singleplayer): closest matches first, and among equally close ones the better-known games.

Chained Together
Shared: Platformer · Adventure · Casual

Portal 2
Shared: Platformer · Singleplayer · Puzzle Platformer

FEZ
Shared: Platformer · Adventure · Singleplayer

Refunct
Shared: 3D Platformer · Platformer · Casual

Supraland
Shared: Adventure · Puzzle Platformer · Singleplayer

Climber Animals: Together
Shared: Platformer · Casual · Physics

A Hat in Time
Shared: 3D Platformer · Adventure · Platformer

Grow Home
Shared: Adventure · Singleplayer · Casual

Portal
Shared: Puzzle Platformer · Singleplayer · 3D Platformer

Getting Over It with Bennett Foddy
Shared: Singleplayer · Platformer · Physics

A Story About My Uncle
Shared: Adventure · Singleplayer · Platformer

Psychonauts
Shared: Platformer · Adventure · Singleplayer

Carry The Glass
Shared: Adventure · Puzzle Platformer · Platformer

Slime Rancher
Shared: Adventure · Singleplayer · Exploration

Kao the Kangaroo: Round 2 (2003 re-release)
Shared: Adventure · Platformer · Casual

Ratchet & Clank: Rift Apart
Shared: Adventure · Singleplayer · 3D Platformer

LIMBO
Shared: Platformer · Puzzle Platformer · Adventure

Human Fall Flat
Shared: Adventure · Puzzle Platformer · Physics

Sonic Frontiers
Shared: Adventure · 3D Platformer · Singleplayer

Sonic Lost World
Shared: Platformer · Adventure · Singleplayer

Sonic Adventure DX
Shared: Platformer · Adventure · 3D Platformer

Pseudoregalia
Shared: 3D Platformer · Platformer · Singleplayer

Hollow Knight
Shared: Platformer · Singleplayer · Adventure

Pumpkin Jack
Shared: Adventure · 3D Platformer · Platformer