Games like HootBox
Games like HootBox include Hollow Knight, Zup! S, Vampire Survivors, Hollow Knight: Silksong, and FEZ. We matched them by the tags players give HootBox on Steam (Casual, Singleplayer, Physics, 2D, and Side Scroller): closest matches first, and among equally close ones the better-known games.

Hollow Knight
Shared: Platformer · 2D · Singleplayer

Zup! S
Shared: Casual · 2D · Physics

Vampire Survivors
Shared: 2D · Singleplayer · Casual

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

FEZ
Shared: Platformer · Singleplayer · Indie

LIMBO
Shared: Indie · Platformer · 2D

BEEP
Shared: Singleplayer · 2D · Platformer

People Playground
Shared: Physics · Singleplayer · 2D

Geometry Dash
Shared: 2D · Singleplayer · Platformer

Peggle Deluxe
Shared: Casual · Singleplayer · 2D

pureya
Shared: Casual · Singleplayer · 2D

Rogue Legacy
Shared: Platformer · Singleplayer · Indie

Zup!
Shared: Casual · 2D · Physics

Timberman
Shared: Casual · Singleplayer · 2D

Skul: The Hero Slayer
Shared: Indie · 2D · Singleplayer

Getting Over It with Bennett Foddy
Shared: Singleplayer · Physics · Casual

Turbo Pug
Shared: Casual · 2D · Indie

Thank Goodness You're Here!
Shared: Casual · 2D · Exploration

Shovel Knight: Treasure Trove
Shared: Platformer · 2D · Indie

Zup! X
Shared: Casual · 2D · Physics

DAVE THE DIVER
Shared: Casual · Singleplayer · Exploration

Zup! 2
Shared: Casual · 2D · Physics

Defy Gravity Extended
Shared: Platformer · Singleplayer · 2D

Zup! F
Shared: Casual · 2D · Physics