Games like Virus Protocol
Games like Virus Protocol include Celeste, Broforce, Skul: The Hero Slayer, Shovel Knight: Treasure Trove, and Katana ZERO. We matched them by the tags players give Virus Protocol on Steam (Action, Platformer, Puzzle Platformer, Hero Shooter, and 2D): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Platformer · Pixel Graphics · 2D

Broforce
Shared: Action · Platformer · 2D

Skul: The Hero Slayer
Shared: Action · 2D · Pixel Graphics

Shovel Knight: Treasure Trove
Shared: Platformer · Pixel Graphics · Action

Katana ZERO
Shared: Action · Platformer · Pixel Graphics

Webbed
Shared: Puzzle Platformer · Cute · Pixel Graphics

Out There Somewhere
Shared: Platformer · Pixel Graphics · Action

MO:Astray
Shared: Action · Puzzle Platformer · Platformer

SANABI
Shared: Action · Pixel Graphics · 2D

The Messenger
Shared: Platformer · Action · 2D

Hollow Knight
Shared: Platformer · 2D · Indie

Gato Roboto
Shared: Action · Platformer · 2D

BlazBlue Entropy Effect
Shared: Action · Platformer · 2D

Defy Gravity Extended
Shared: Platformer · Puzzle Platformer · Action

Freedom Planet
Shared: Platformer · Action · 2D

Super Meat Boy
Shared: Platformer · 2D · Pixel Graphics

Bloodstained: Curse of the Moon
Shared: Action · Platformer · Pixel Graphics

ANIMAL WELL
Shared: Puzzle Platformer · Platformer · Pixel Graphics

LIMBO
Shared: Puzzle Platformer · Platformer · 2D

Sonic Mania
Shared: Platformer · 2D · Action

ElecHead
Shared: Puzzle Platformer · Platformer · Action

Gravity Circuit
Shared: Action · Platformer · 2D

Rogue Legacy
Shared: Platformer · Action · 2D

Rain World
Shared: Platformer · Pixel Graphics · 2D