Games like Chaos Domain
Games like Chaos Domain include Broforce, My Friend Pedro, Cuphead, Rocketbirds: Hardboiled Chicken, and Shank 2. We matched them by the tags players give Chaos Domain on Steam (Action, Indie, Platformer, Shooter, and Side Scroller): closest matches first, and among equally close ones the better-known games.

Broforce
Shared: Action · Platformer · Co-op

My Friend Pedro
Shared: Action · Indie · Shooter

Cuphead
Shared: Platformer · Co-op · Indie

Rocketbirds: Hardboiled Chicken
Shared: Indie · Action · Platformer

Shank 2
Shared: Action · Indie · Side Scroller

Shank
Shared: Action · Indie · Side Scroller

Huntdown
Shared: Action · Shooter · Side Scroller

Intrusion 2
Shared: Action · Indie · Platformer

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

BattleBlock Theater®
Shared: Platformer · Co-op · Local Co-Op

Zombotron
Shared: Action · Indie · Shooter

STAR WARS™ Battlefront™ II
Shared: Shooter · Action · Singleplayer

Bright Memory: Infinite
Shared: Action · Indie · Shooter

Awesomenauts
Shared: Action · Platformer · Indie

HELLDIVERS™ 2
Shared: Action · Shooter · Co-op

Halo Infinite
Shared: Action · Shooter · Singleplayer

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

Call of Duty®: Black Ops III
Shared: Action · Shooter · Co-op

Rogue Legacy
Shared: Platformer · Indie · Action

Guns, Gore & Cannoli
Shared: Action · Side Scroller · Co-op

Serious Sam Double D XXL
Shared: Action · Indie · Platformer

METAL SLUG 3
Shared: Action · Side Scroller · Co-op

Ready or Not
Shared: Shooter · Co-op · Action

Guns, Gore and Cannoli 2
Shared: Action · Side Scroller · Co-op