Games like Submansion
Games like Submansion include The Stanley Parable, The Henry Stickmin Collection, Reventure, Five Nights at Freddy's: Into the Pit, and NEEDY STREAMER OVERLOAD. We matched them by the tags players give Submansion on Steam (Visual Novel, Multiple Endings, Adventure, Psychological, and 2D): closest matches first, and among equally close ones the better-known games.

The Stanley Parable
Shared: Comedy · Psychological · Indie

The Henry Stickmin Collection
Shared: Multiple Endings · Comedy · 2D

Reventure
Shared: Adventure · Multiple Endings · Indie

Five Nights at Freddy's: Into the Pit
Shared: Adventure · 2D · Multiple Endings

NEEDY STREAMER OVERLOAD
Shared: Visual Novel · Multiple Endings · Psychological

Deponia
Shared: Adventure · Point & Click · Comedy

The Coffin of Andy and Leyley
Shared: Psychological · Multiple Endings · Visual Novel

Milk outside a bag of milk outside a bag of milk
Shared: Visual Novel · Multiple Endings · Psychological

There Is No Game: Wrong Dimension
Shared: Adventure · Indie · Point & Click

The NOexistenceN of you AND me
Shared: Visual Novel · Multiple Endings · Psychological

Looking Up I See Only A Ceiling
Shared: Adventure · Psychological · Multiple Endings

Undertale
Shared: Multiple Endings · 2D · Indie

Hollow Knight
Shared: 2D · Indie · Adventure

That's not my Neighbor
Shared: Adventure · Point & Click · Multiple Endings

Edna & Harvey: The Breakout
Shared: Adventure · Point & Click · Comedy

Raging Loop
Shared: Visual Novel · Adventure · Psychological

Otaku's Adventure
Shared: Multiple Endings · Visual Novel · Adventure

The Test
Shared: Multiple Endings · Psychological · Visual Novel

Hollow Knight: Silksong
Shared: 2D · Indie · Adventure

Soul Gambler
Shared: Visual Novel · Adventure · Multiple Endings

Papers, Please
Shared: Multiple Endings · Indie · Point & Click

Five Nights at Freddy's: Security Breach
Shared: Multiple Endings · Singleplayer · Horror

Chaos on Deponia
Shared: Adventure · Comedy · Point & Click

The Wolf Among Us
Shared: Adventure · Multiple Endings · Visual Novel