Games like MainFrames
Games like MainFrames include Webbed, LIMBO, Celeste, Portal 2, and FEZ. We matched them by the tags players give MainFrames on Steam (Adventure, Physics, Platformer, Puzzle, and Puzzle Platformer): closest matches first, and among equally close ones the better-known games.

Webbed
Shared: Physics · 2D Platformer · Cute

LIMBO
Shared: Puzzle Platformer · Platformer · Puzzle

Celeste
Shared: Platformer · Pixel Graphics · 2D Platformer

Portal 2
Shared: Platformer · Puzzle · Puzzle Platformer

FEZ
Shared: Platformer · Puzzle · Adventure

Out There Somewhere
Shared: Platformer · Adventure · Puzzle

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

ANIMAL WELL
Shared: Puzzle · Platformer · Puzzle Platformer

Pizza Tower
Shared: 2D Platformer · Platformer · Pixel Graphics

Öoo
Shared: Puzzle Platformer · Puzzle · 2D Platformer

Neva
Shared: Adventure · Platformer · Puzzle

ElecHead
Shared: Platformer · Puzzle · Puzzle Platformer

Trine 2: Complete Story
Shared: Platformer · Puzzle Platformer · Puzzle

Planet of Lana
Shared: Puzzle Platformer · Puzzle · Adventure

Hue
Shared: Adventure · Puzzle · Platformer

SANABI
Shared: Adventure · 2D Platformer · Pixel Graphics

Zup! 2
Shared: Puzzle · Physics · 2D

Mind Over Magnet
Shared: Adventure · Puzzle · Puzzle Platformer

Human Fall Flat
Shared: Puzzle · Physics · Adventure

Braid
Shared: Puzzle · Puzzle Platformer · Platformer

BEEP
Shared: Adventure · Platformer · Physics

Sonic Mania
Shared: Platformer · Adventure · 2D

Moonleap
Shared: Platformer · Puzzle · Puzzle Platformer

Viewfinder
Shared: Puzzle · Puzzle Platformer · Adventure