Games like Robby's Adventure
Games like Robby's Adventure include Hollow Knight, Stray, Brothers - A Tale of Two Sons, A Story About My Uncle, and Hollow Knight: Silksong. We matched them by the tags players give Robby's Adventure on Steam (Adventure, Platformer, Side Scroller, Robots, and Family Friendly): closest matches first, and among equally close ones the better-known games.

Hollow Knight
Shared: Platformer · Indie · Adventure

Stray
Shared: Adventure · Robots · Singleplayer

Brothers - A Tale of Two Sons
Shared: Adventure · Indie · Controller

A Story About My Uncle
Shared: Adventure · Platformer · Indie

Hollow Knight: Silksong
Shared: Indie · Platformer · Adventure

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

The Last Campfire
Shared: Adventure · Indie · Singleplayer

LIMBO
Shared: Platformer · Indie · Adventure

Celeste
Shared: Platformer · Indie · Adventure

BEEP
Shared: Platformer · Adventure · Indie

Mark of the Ninja
Shared: Platformer · Indie · Adventure

Florence
Shared: Adventure · Indie · Casual

Never Alone (Kisima Ingitchuna)
Shared: Platformer · Adventure · Indie

GRIS
Shared: Adventure · Indie · Platformer

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

Pinstripe
Shared: Adventure · Indie · Platformer

Little Nightmares
Shared: Adventure · Singleplayer · Indie

Toki Tori
Shared: Platformer · Indie · Casual

Pikuniku
Shared: Adventure · Indie · Casual

Nihilumbra
Shared: Adventure · Platformer · Indie

Chained Together
Shared: Adventure · Platformer · Casual

Slime Rancher
Shared: Adventure · Singleplayer · Cute

Deadlight
Shared: Platformer · Adventure · Indie

Ratchet & Clank: Rift Apart
Shared: Adventure · Singleplayer · Family Friendly