Games like Sumin's Tower:Session No.5
Games like Sumin's Tower:Session No.5 include A Story About My Uncle, Refunct, Portal 2, VHOLUME, and Slime Rancher 2. We matched them by the tags players give Sumin's Tower:Session No.5 on Steam (Adventure, 3D Platformer, Platformer, First-Person, and Casual): closest matches first, and among equally close ones the better-known games.

A Story About My Uncle
Shared: Adventure · First-Person · Platformer

Refunct
Shared: 3D Platformer · First-Person · Platformer

Portal 2
Shared: Platformer · First-Person · 3D Platformer

VHOLUME
Shared: 3D Platformer · First-Person · Platformer

Slime Rancher 2
Shared: Adventure · First-Person · Relaxing

Chained Together
Shared: Adventure · Platformer · Casual

Portal
Shared: 3D Platformer · First-Person · Sci-fi

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

Road 96
Shared: First-Person · Adventure · Multiple Endings

Sonic Adventure DX
Shared: Platformer · 3D Platformer · Adventure

GRIS
Shared: Adventure · Platformer · Atmospheric

Hollow Knight
Shared: Platformer · Adventure · Indie

PEAK
Shared: Adventure · First-Person · 3D

Valley
Shared: Adventure · First-Person · 3D Platformer

Climb The Backrooms
Shared: Adventure · Platformer · 3D Platformer

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

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

Sable
Shared: Adventure · Choose Your Own Adventure · Multiple Endings

Firewatch
Shared: Adventure · First-Person · Atmospheric

Grow Up
Shared: Adventure · 3D Platformer · Casual

Five Nights at Freddy's: Security Breach
Shared: First-Person · Multiple Endings · Adventure

The Last Campfire
Shared: Adventure · 3D Platformer · Indie

A Short Hike
Shared: Adventure · Relaxing · Casual

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