Games like Orbital Defense Force
Games like Orbital Defense Force include Enter the Gungeon, Risk of Rain 2, Nuclear Throne, Vampire Survivors, and Risk of Rain Returns. We matched them by the tags players give Orbital Defense Force on Steam (Multiplayer, Action Roguelike, Online Co-Op, Bullet Hell, and Action): closest matches first, and among equally close ones the better-known games.

Enter the Gungeon
Shared: Action Roguelike · Bullet Hell · Multiplayer

Risk of Rain 2
Shared: Action Roguelike · Multiplayer · Action

Nuclear Throne
Shared: Action Roguelike · Bullet Hell · Difficult

Vampire Survivors
Shared: Action Roguelike · Bullet Hell · Pixel Graphics

Risk of Rain Returns
Shared: Action Roguelike · Multiplayer · Online Co-Op

BALL x PIT
Shared: Action · Bullet Hell · Action Roguelike

HELLDIVERS™ 2
Shared: Online Co-Op · Multiplayer · Action

SYNTHETIK: Legion Rising
Shared: Action Roguelike · Action · Online Co-Op

Risk of Rain (2013)
Shared: Action Roguelike · Action · Online Co-Op

The Spell Brigade
Shared: Online Co-Op · Bullet Hell · Action Roguelike

Cuphead
Shared: Difficult · Multiplayer · Bullet Hell

Ravenswatch
Shared: Action Roguelike · Online Co-Op · Multiplayer

Realm of the Mad God Exalt
Shared: Bullet Hell · Action Roguelike · Pixel Graphics

Star of Providence
Shared: Action Roguelike · Bullet Hell · Shoot 'Em Up

Hero Siege
Shared: Action Roguelike · Multiplayer · Pixel Graphics

Counter-Strike 2
Shared: Multiplayer · Action · Online Co-Op

Just Shapes & Beats
Shared: Multiplayer · Bullet Hell · Difficult

20 Minutes Till Dawn
Shared: Action Roguelike · Bullet Hell · Shoot 'Em Up

Among Us
Shared: Multiplayer · Online Co-Op · 2D

Heroes of Hammerwatch
Shared: Action Roguelike · Multiplayer · Online Co-Op

Skul: The Hero Slayer
Shared: Action Roguelike · Action · Pixel Graphics

Children of Morta
Shared: Multiplayer · Online Co-Op · Action Roguelike

HELLDIVERS™ Dive Harder Edition
Shared: Online Co-Op · Multiplayer · Action

Vagante
Shared: Action Roguelike · Difficult · Action