Games like Rainbow Duck
Games like Rainbow Duck include Kao the Kangaroo: Round 2 (2003 re-release), Pikuniku, SpeedRunners, Hollow Knight, and Hollow Knight: Silksong. We matched them by the tags players give Rainbow Duck on Steam (Action, Indie, Casual, Sports, and Racing): closest matches first, and among equally close ones the better-known games.
Kao the Kangaroo: Round 2 (2003 re-release)
Shared: Action · Casual · Adventure
Pikuniku
Shared: Indie · Casual · Adventure
SpeedRunners
Shared: Indie · Racing · Action
Hollow Knight
Shared: Indie · Difficult · Adventure
Hollow Knight: Silksong
Shared: Indie · Difficult · Adventure
BEEP
Shared: Indie · Adventure · Action
Golf With Your Friends
Shared: Casual · Sports · Indie
Minimalism
Shared: Indie · Action · Casual
Skul: The Hero Slayer
Shared: Action · Indie · 2D
Timberman
Shared: Casual · Indie · Action
Russian Life Simulator
Shared: Indie · Action · Casual
Superflight
Shared: Indie · Casual · Action
No Time To Explain Remastered
Shared: Action · Indie · Casual
Gang Beasts
Shared: Action · Casual · Indie
SANABI
Shared: Action · Indie · Adventure
A Dance of Fire and Ice
Shared: Indie · Casual · Difficult
Super Meat Boy Forever
Shared: Indie · Action · Runner
Retrowave
Shared: Indie · Racing · Casual
Super Fancy Pants Adventure
Shared: Action · Indie · Casual
Dust: An Elysian Tail
Shared: Action · Indie · Adventure
Nine Sols
Shared: Action · Indie · 2D
Jump King
Shared: Indie · Action · Adventure
Need for Speed™ Heat
Shared: Racing · Action · Adventure
Wobbly Life
Shared: Adventure · Action · Casual