Games like Power of Two
Games like Power of Two include Broforce, BALL x PIT, Streets of Rage 4, METAL SLUG 3, and Sky Force Reloaded. We matched them by the tags players give Power of Two on Steam (Action, Arcade, Top-Down Shooter, 2D, and Abstract): closest matches first, and among equally close ones the better-known games.

Broforce
Shared: Action · 2D · Co-op

BALL x PIT
Shared: Action · Arcade · Top-Down Shooter

Streets of Rage 4
Shared: Action · 2D · Arcade

METAL SLUG 3
Shared: Arcade · Action · 2D

Sky Force Reloaded
Shared: Arcade · Top-Down Shooter · Action

Hotline Miami
Shared: Action · Top-Down · Indie

METAL SLUG X
Shared: Action · Arcade · 2D

UFO 50
Shared: Action · Arcade · 2D

Hotline Miami 2: Wrong Number
Shared: Action · Top-Down · Retro

METAL SLUG
Shared: Action · Arcade · 2D

Splatter - Zombiecalypse Now
Shared: Action · Top-Down Shooter · Top-Down

Cyberhunt
Shared: Action · Arcade · 2D

Zombieville USA 3D
Shared: Action · Arcade · Top-Down Shooter

Kill The Crows
Shared: Action · Arcade · Top-Down Shooter

PAC-MAN™ Championship Edition DX+
Shared: Arcade · Action · Retro

UBERMOSH Vol.3
Shared: Action · Arcade · Top-Down Shooter

Shovel Knight: Treasure Trove
Shared: Action · 2D · Retro

HELLDIVERS™ Dive Harder Edition
Shared: Top-Down Shooter · Action · Top-Down

Planes, Bullets and Vodka
Shared: Action · Arcade · 2D

64.0
Shared: Action · Abstract · Retro

12 is Better Than 6
Shared: Action · Top-Down Shooter · 2D

Revolution Ace
Shared: Action · Arcade · Top-Down

Crimsonland
Shared: Action · Top-Down Shooter · Top-Down

Vampire Survivors
Shared: 2D · Arcade · Action