Games like Now Testing: 407
Games like Now Testing: 407 include Portal 2, Portal, A Story About My Uncle, Human Fall Flat, and LIMBO. We matched them by the tags players give Now Testing: 407 on Steam (Adventure, Puzzle, Action, Platformer, and Puzzle Platformer): closest matches first, and among equally close ones the better-known games.

Portal 2
Shared: Puzzle · Platformer · First-Person

Portal
Shared: Puzzle · Puzzle Platformer · First-Person

A Story About My Uncle
Shared: Adventure · First-Person · Platformer

Human Fall Flat
Shared: Puzzle · Adventure · Puzzle Platformer

LIMBO
Shared: Puzzle · Puzzle Platformer · Platformer

Refunct
Shared: 3D Platformer · Puzzle Platformer · First-Person

Chained Together
Shared: Adventure · Platformer · Casual

Pikuniku
Shared: Adventure · Puzzle · Casual

Planet of Lana
Shared: Action · Puzzle Platformer · Puzzle

Climb The Backrooms
Shared: Adventure · Puzzle · Platformer

Psychonauts
Shared: Adventure · Platformer · Action

Oddworld: New 'n' Tasty
Shared: Adventure · Platformer · Puzzle Platformer

Nihilumbra
Shared: Adventure · Puzzle · Platformer

Little Nightmares
Shared: Adventure · Puzzle · Puzzle Platformer

There Is No Game: Wrong Dimension
Shared: Puzzle · Adventure · Casual

PEAK
Shared: Adventure · First-Person · 3D

FEZ
Shared: Puzzle · Platformer · Adventure

Seen
Shared: Adventure · Puzzle · Platformer

Quantum Conundrum
Shared: Puzzle · Puzzle Platformer · First-Person

Viewfinder
Shared: Puzzle · Puzzle Platformer · Adventure

Ori and the Will of the Wisps
Shared: Platformer · Adventure · Action

Pinstripe
Shared: Adventure · Casual · Puzzle

INSIDE
Shared: Puzzle Platformer · Adventure · Puzzle

Supraland
Shared: Adventure · Puzzle Platformer · Puzzle