Games like Once Up
Games like Once Up include Trine 2: Complete Story, Portal, Webbed, Trine Enchanted Edition, and Planet of Lana. We matched them by the tags players give Once Up on Steam (Action, Casual, Puzzle Platformer, Physics, and Hand-drawn): closest matches first, and among equally close ones the better-known games.

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

Portal
Shared: Puzzle Platformer · Puzzle · Physics

Webbed
Shared: Physics · Puzzle Platformer · 2D Platformer

Trine Enchanted Edition
Shared: Puzzle Platformer · Physics · 2D Platformer

Planet of Lana
Shared: Action · Puzzle Platformer · Puzzle

Human Fall Flat
Shared: Physics · Puzzle · Puzzle Platformer

Portal 2
Shared: Puzzle · Puzzle Platformer · Singleplayer

Defy Gravity Extended
Shared: Puzzle Platformer · Action · Puzzle

Zup!
Shared: Casual · Puzzle · Physics

Hidden Folks
Shared: Casual · Hand-drawn · Puzzle

Zup! 2
Shared: Casual · Puzzle · Physics

LIMBO
Shared: Puzzle Platformer · Puzzle · Indie

Zup! 8
Shared: Casual · Puzzle · Physics

Thank Goodness You're Here!
Shared: Casual · Hand-drawn · Exploration

The Bridge
Shared: Puzzle Platformer · Hand-drawn · Physics

FEZ
Shared: Puzzle · Casual · Exploration

Monument Valley 2
Shared: Casual · Action · Puzzle

Leap Year
Shared: Puzzle Platformer · Exploration · 2D Platformer

Braid
Shared: Puzzle Platformer · Puzzle · 2D Platformer

Gang Beasts
Shared: Action · Physics · Casual

Zup! 3
Shared: Casual · Puzzle · Physics

Zup! X
Shared: Casual · Puzzle · Physics

Supraland
Shared: Puzzle Platformer · Exploration · Physics

Zup! S
Shared: Casual · Puzzle · Physics