Games like Gunborg: Dark Matters
Games like Gunborg: Dark Matters include SANABI, Warhammer 40,000: Shootas, Blood & Teef, Touhou Luna Nights, Anomaly Agent, and Huntdown. We matched them by the tags players give Gunborg: Dark Matters on Steam (Side Scroller, 2D Platformer, Bullet Hell, Twin Stick Shooter, and Platformer): closest matches first, and among equally close ones the better-known games.

SANABI
Shared: 2D Platformer · Cyberpunk · Platformer

Warhammer 40,000: Shootas, Blood & Teef
Shared: Side Scroller · 2D Platformer · Bullet Hell

Touhou Luna Nights
Shared: Side Scroller · Bullet Hell · Platformer

Anomaly Agent
Shared: Side Scroller · 2D Platformer · Platformer

Huntdown
Shared: Side Scroller · Shooter · Platformer

Nitro Express
Shared: Side Scroller · 2D Platformer · Shooter

Rise & Shine
Shared: Side Scroller · 2D Platformer · Bullet Hell

Broforce
Shared: Platformer · Side Scroller · 2D

Touhou Hero of Ice Fairy
Shared: Bullet Hell · Side Scroller · Platformer

Momodora: Reverie Under The Moonlight
Shared: 2D Platformer · Side Scroller · Female Protagonist

Celeste
Shared: 2D Platformer · Platformer · Female Protagonist

Katana ZERO
Shared: 2D Platformer · Platformer · Action

Rabi-Ribi
Shared: Bullet Hell · Side Scroller · Female Protagonist

Mina the Hollower
Shared: 2D Platformer · Action-Adventure · Platformer

TEVI
Shared: Bullet Hell · Side Scroller · Action-Adventure

Terminator 2D: NO FATE
Shared: Side Scroller · 2D Platformer · Arcade

Super Time Force Ultra
Shared: Side Scroller · Bullet Hell · 2D Platformer

Freedom Planet 2
Shared: Side Scroller · Platformer · Female Protagonist

Afterimage
Shared: 2D Platformer · Side Scroller · Female Protagonist

Blade Assault
Shared: 2D Platformer · Platformer · Side Scroller

Exit the Gungeon
Shared: Bullet Hell · Arcade · 2D Platformer

Alex Jones: NWO Wars
Shared: 2D Platformer · Side Scroller · Shooter

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

BlazBlue Entropy Effect
Shared: Platformer · Action-Adventure · 2D