Games like Inflatum
Games like Inflatum include Donut County, Tinykin, Pikuniku, The Last Campfire, and Chained Together. We matched them by the tags players give Inflatum on Steam (Adventure, Casual, Action-Adventure, Puzzle, and 3D Platformer): closest matches first, and among equally close ones the better-known games.

Donut County
Shared: Casual · Puzzle · Indie

Tinykin
Shared: 3D Platformer · Action-Adventure · Puzzle

Pikuniku
Shared: Adventure · Casual · Puzzle

The Last Campfire
Shared: Adventure · Puzzle · Indie

Chained Together
Shared: Adventure · Casual · 3D Platformer

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

A Short Hike
Shared: Adventure · Casual · Indie

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

TOEM: A Photo Adventure
Shared: Adventure · Puzzle · Casual

Scribblenauts Unlimited
Shared: Casual · Adventure · Puzzle

Kao the Kangaroo: Round 2 (2003 re-release)
Shared: Adventure · Casual · 3D Platformer

The Plucky Squire
Shared: Adventure · Action-Adventure · 3D Platformer

Human Fall Flat
Shared: Puzzle · Adventure · Funny

Carto
Shared: Puzzle · Adventure · Indie

Deaths Door
Shared: 3D Platformer · Adventure · Action-Adventure

Slime Rancher
Shared: Adventure · Cute · Casual

Another Crab's Treasure
Shared: 3D Platformer · Action-Adventure · Cartoony

Portal 2
Shared: Puzzle · 3D Platformer · Action-Adventure

Lil Gator Game
Shared: Casual · Cute · Adventure

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

Spirit of the North
Shared: Adventure · Casual · Puzzle

Hidden Folks
Shared: Casual · Puzzle · Indie

INSIDE
Shared: 2.5D · Adventure · Indie

Moss VR
Shared: Adventure · Puzzle · Action-Adventure