Games like Sweet Island
Games like Sweet Island include A Hat in Time, Pumpkin Jack, Spyro™ Reignited Trilogy, Ratchet & Clank: Rift Apart, and Kao the Kangaroo: Round 2 (2003 re-release). We matched them by the tags players give Sweet Island on Steam (3D Platformer, Adventure, Action, Cartoony, and Runner): closest matches first, and among equally close ones the better-known games.

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

Pumpkin Jack
Shared: Adventure · 3D Platformer · Action

Spyro™ Reignited Trilogy
Shared: 3D Platformer · Adventure · Action

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

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

Crash Bandicoot™ N. Sane Trilogy
Shared: 3D Platformer · Adventure · Singleplayer

Slime Rancher
Shared: Adventure · Cute · Singleplayer

Psychonauts 2
Shared: 3D Platformer · Adventure · Singleplayer

Deaths Door
Shared: 3D Platformer · Cartoony · Action

Yooka-Laylee
Shared: 3D Platformer · Adventure · Action

Psychonauts
Shared: Adventure · Action · 3D Platformer

TY the Tasmanian Tiger
Shared: 3D Platformer · Action · Adventure

Portal 2
Shared: Singleplayer · 3D Platformer · Platformer

Haste
Shared: 3D Platformer · Action · Runner

Crash Bandicoot™ 4: It’s About Time
Shared: 3D Platformer · Action · Adventure

SONIC X SHADOW GENERATIONS
Shared: 3D Platformer · Action · Adventure

SpongeBob SquarePants: Battle for Bikini Bottom - Rehydrated
Shared: 3D Platformer · Adventure · Action

Sonic Frontiers
Shared: 3D Platformer · Adventure · Action

ALTF4
Shared: 3D Platformer · Runner · Action

Suzy Cube
Shared: 3D Platformer · Adventure · Cartoony

Sonic Lost World
Shared: Adventure · 3D Platformer · Singleplayer

Sonic Adventure 2
Shared: 3D Platformer · Action · Adventure

Cat Quest
Shared: Adventure · Action · Cute

Sonic Forces
Shared: 3D Platformer · Adventure · Action