Games like Sisyphus.12.20.03
Games like Sisyphus.12.20.03 include Hollow Knight, Chained Together, LIMBO, A Story About My Uncle, and Florence. We matched them by the tags players give Sisyphus.12.20.03 on Steam (Adventure, Casual, Platformer, Visual Novel, and 3D Platformer): closest matches first, and among equally close ones the better-known games.

Hollow Knight
Shared: Platformer · 2D · Adventure

Chained Together
Shared: Adventure · Platformer · Casual

LIMBO
Shared: Platformer · Adventure · 2D

A Story About My Uncle
Shared: Adventure · Platformer · 3D Platformer

Florence
Shared: Casual · Adventure · Visual Novel

GRIS
Shared: Adventure · Platformer · Atmospheric

Pikuniku
Shared: Adventure · Casual · Cute

INSIDE
Shared: 2.5D · Adventure · Atmospheric

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

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

Pinstripe
Shared: Adventure · Casual · Platformer

Funi Raccoon Game
Shared: Adventure · Casual · Platformer

Castle of Illusion
Shared: Adventure · Platformer · Casual

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

FAR: Lone Sails
Shared: Adventure · 2.5D · Atmospheric

Chill with You : Lo-Fi Story
Shared: Casual · Visual Novel · Adventure

FEZ
Shared: Platformer · Adventure · Casual

The Last Campfire
Shared: Adventure · Cute · Atmospheric

Nihilumbra
Shared: Adventure · Platformer · Casual

Little Nightmares
Shared: Adventure · Atmospheric · Platformer

The Plucky Squire
Shared: Adventure · 3D Platformer · 2D

ATLYSS
Shared: Adventure · 3D Platformer · Cute

Fox Hime Zero
Shared: Visual Novel · Casual · Adventure

Rain World
Shared: Platformer · Adventure · Atmospheric