Games like Ato
Games like Ato include Hollow Knight, Hollow Knight: Silksong, Ori and the Will of the Wisps, MIO: Memories in Orbit, and Rain World. We matched them by the tags players give Ato on Steam (Metroidvania, Atmospheric, Indie, 2D Platformer, and Exploration): closest matches first, and among equally close ones the better-known games.

Hollow Knight
Shared: Metroidvania · Indie · Atmospheric

Hollow Knight: Silksong
Shared: Metroidvania · Indie · Singleplayer

Ori and the Will of the Wisps
Shared: Metroidvania · Atmospheric · Singleplayer

MIO: Memories in Orbit
Shared: Metroidvania · Atmospheric · Exploration

Rain World
Shared: Atmospheric · Indie · Exploration

Prince of Persia The Lost Crown
Shared: Metroidvania · 2D Platformer · Exploration

The Witness
Shared: Exploration · Indie · Atmospheric

Chants of Sennaar
Shared: Indie · Singleplayer · Atmospheric

ANIMAL WELL
Shared: Metroidvania · Exploration · Atmospheric

F.I.S.T.: Forged In Shadow Torch
Shared: Metroidvania · 2D Platformer · Singleplayer

Hyper Light Drifter
Shared: Atmospheric · Indie · Singleplayer

Stray
Shared: Atmospheric · Singleplayer · Exploration

FAR: Lone Sails
Shared: Atmospheric · Exploration · Singleplayer

TUNIC
Shared: Metroidvania · Exploration · Action-Adventure

Antichamber
Shared: Indie · Exploration · Singleplayer

Crypt Custodian
Shared: Metroidvania · Atmospheric · Exploration

Cairn
Shared: Indie · Exploration · Atmospheric

SANABI
Shared: 2D Platformer · Indie · Singleplayer

Souldiers
Shared: Metroidvania · Singleplayer · Action-Adventure

Constance
Shared: Metroidvania · Indie · Action-Adventure

Rise of the Tomb Raider™
Shared: Singleplayer · Exploration · Action-Adventure

Nine Sols
Shared: Metroidvania · Indie · Atmospheric

Hob
Shared: Indie · Singleplayer · Metroidvania

Momodora: Reverie Under The Moonlight
Shared: Metroidvania · 2D Platformer · Exploration