Games like Systematic Immunity
Games like Systematic Immunity include Dust: An Elysian Tail, Hollow Knight, Deadlight, Skul: The Hero Slayer, and Rogue Legacy 2. We matched them by the tags players give Systematic Immunity on Steam (Action, Indie, Adventure, and Platformer): closest matches first, and among equally close ones the better-known games.

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

Hollow Knight
Shared: Platformer · Indie · Adventure

Deadlight
Shared: Action · Indie · Platformer

Skul: The Hero Slayer
Shared: Action · Indie · Platformer

Rogue Legacy 2
Shared: Action · Platformer · Indie

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

MO:Astray
Shared: Action · Indie · Adventure

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

Pumpkin Jack
Shared: Action · Adventure · Indie

SANABI
Shared: Action · Adventure · Indie

Mark of the Ninja
Shared: Indie · Platformer · Action

BEEP
Shared: Indie · Adventure · Platformer

Broforce
Shared: Action · Platformer · Indie

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

Hollow Knight: Silksong
Shared: Indie · Platformer · Adventure

Dungeon Munchies
Shared: Action · Indie · Adventure

Monster Boy and the Cursed Kingdom
Shared: Action · Adventure · Indie

SteamWorld Dig 2
Shared: Adventure · Indie · Action

Out There Somewhere
Shared: Indie · Platformer · Adventure

Super Fancy Pants Adventure
Shared: Action · Indie · Adventure

Seen
Shared: Indie · Adventure · Action

Gato Roboto
Shared: Indie · Action · Adventure

Pikuniku
Shared: Indie · Adventure · Action

Rocketbirds: Hardboiled Chicken
Shared: Indie · Action · Platformer