Games like SU42: Hired Gun
Games like SU42: Hired Gun include Broforce, SANABI, Huntdown, Terminator 2D: NO FATE, and Shovel Knight: Treasure Trove. We matched them by the tags players give SU42: Hired Gun on Steam (Hand-drawn, Side Scroller, Hero Shooter, 2D Platformer, and 2D): closest matches first, and among equally close ones the better-known games.

Broforce
Shared: Pixel Graphics · 2D · Platformer

SANABI
Shared: Pixel Graphics · 2D Platformer · 2D

Huntdown
Shared: Side Scroller · Pixel Graphics · 2D

Terminator 2D: NO FATE
Shared: Side Scroller · 2D Platformer · Pixel Graphics

Shovel Knight: Treasure Trove
Shared: Pixel Graphics · Platformer · 2D

Celeste
Shared: Pixel Graphics · 2D Platformer · Platformer

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

Sonic Mania
Shared: 2D · Platformer · Pixel Graphics

Katana ZERO
Shared: Pixel Graphics · 2D Platformer · Platformer

The Messenger
Shared: Platformer · Retro · Pixel Graphics

Gravity Circuit
Shared: Platformer · 2D · Pixel Graphics

Pizza Tower
Shared: 2D Platformer · Platformer · Pixel Graphics

NINJA GAIDEN: Ragebound
Shared: 2D Platformer · Side Scroller · Platformer

Momodora: Reverie Under The Moonlight
Shared: Side Scroller · 2D Platformer · Pixel Graphics

UFO 50
Shared: Pixel Graphics · 2D · Retro

Bloodstained: Curse of the Moon
Shared: Pixel Graphics · Side Scroller · 2D

VVVVVV
Shared: Pixel Graphics · 2D Platformer · Platformer

Contra: Operation Galuga
Shared: 2D Platformer · Side Scroller · Platformer

Sonic Origins
Shared: 2D Platformer · Pixel Graphics · Retro

Cuphead
Shared: Platformer · 2D · Hand-drawn

Contra Anniversary Collection
Shared: Side Scroller · 2D · Retro

SHINOBI: Art of Vengeance
Shared: 2D Platformer · Platformer · Hand-drawn

Skul: The Hero Slayer
Shared: Pixel Graphics · 2D · Side Scroller

Axiom Verge
Shared: Pixel Graphics · Platformer · 2D