Games like RRRR
Games like RRRR include Broforce, Shovel Knight: Treasure Trove, Pikuniku, LIMBO, and Rogue Legacy 2. We matched them by the tags players give RRRR on Steam (Action, Indie, Casual, Adventure, and Massively Multiplayer): closest matches first, and among equally close ones the better-known games.

Broforce
Shared: Action · Indie · Platformer

Shovel Knight: Treasure Trove
Shared: Indie · Platformer · Action

Pikuniku
Shared: Indie · Casual · Adventure

LIMBO
Shared: Indie · Platformer · Adventure

Rogue Legacy 2
Shared: Action · Indie · Platformer

UFO 50
Shared: Indie · Action · Retro

Defy Gravity Extended
Shared: Indie · Platformer · Action

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

BEEP
Shared: Indie · Adventure · Platformer

Chained Together
Shared: Adventure · Casual · Platformer

Dungeon Munchies
Shared: Action · Indie · Adventure

SANABI
Shared: Action · Adventure · Indie

Super Fancy Pants Adventure
Shared: Action · Indie · Adventure

Streets of Rage 4
Shared: Action · Indie · 2D

Dust: An Elysian Tail
Shared: Action · Indie · Platformer

Out There Somewhere
Shared: Indie · Platformer · Adventure

Cyberhunt
Shared: Action · Indie · Casual

Sonic Mania
Shared: Platformer · 2D · Action

Mark of the Ninja
Shared: Indie · Action · Platformer

ICEY
Shared: Action · Indie · Adventure

Angry Video Game Nerd Adventures
Shared: Indie · Action · Platformer

Deadlight
Shared: Action · Indie · Platformer

BADLAND: Game of the Year Edition
Shared: Indie · Adventure · Action

Gato Roboto
Shared: Indie · Action · Adventure