Games like Mechaguard
Games like Mechaguard include Celeste, Hollow Knight, Cuphead, Rain World, and Super Meat Boy. We matched them by the tags players give Mechaguard on Steam (Arena Shooter, Shoot 'Em Up, Difficult, Platformer, and Mechs): closest matches first, and among equally close ones the better-known games.

Celeste
Shared: Difficult · Platformer · Pixel Graphics

Hollow Knight
Shared: Platformer · Difficult · 2D

Cuphead
Shared: Difficult · Platformer · 2D

Rain World
Shared: Difficult · Platformer · 2D

Super Meat Boy
Shared: Difficult · Platformer · 2D

Katana ZERO
Shared: Platformer · Action · Pixel Graphics

Geometry Dash
Shared: Difficult · 2D · Platformer

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

SANABI
Shared: Action · Pixel Graphics · 2D

Hollow Knight: Silksong
Shared: Difficult · 2D · Platformer

Shovel Knight: Treasure Trove
Shared: Platformer · 2D · Difficult

Intrusion 2
Shared: Platformer · Action · 2D

Nine Sols
Shared: Difficult · Platformer · 2D

Jump King
Shared: Difficult · Platformer · 2D

Bit Blaster XL
Shared: Shoot 'Em Up · Difficult · 2D

Blasphemous
Shared: 2D · Difficult · Pixel Graphics

Broforce
Shared: Action · Platformer · 2D

Zombotron
Shared: 2D · Action · Shoot 'Em Up

Airscape - The Fall of Gravity
Shared: Shoot 'Em Up · Difficult · Platformer

Downwell
Shared: Platformer · Difficult · Pixel Graphics

VVVVVV
Shared: Platformer · Difficult · Pixel Graphics

The Messenger
Shared: Platformer · 2D · Pixel Graphics

Kero Blaster
Shared: Shoot 'Em Up · Platformer · Difficult

Risk of Rain (2013)
Shared: Platformer · Action · Difficult