Games like PaddleUP!
Games like PaddleUP! include Broforce, Vampire Survivors, Streets of Rage 4, Awesomenauts, and Cuphead. We matched them by the tags players give PaddleUP! on Steam (Action, Arcade, 2D, Linear, and Score Attack): closest matches first, and among equally close ones the better-known games.

Broforce
Shared: Action · 2D · Co-op

Vampire Survivors
Shared: 2D · Arcade · Action

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

Awesomenauts
Shared: 2D · Action · Multiplayer

Cuphead
Shared: 2D · Co-op · Local Co-Op

Need for Speed™ Heat
Shared: Action · Arcade · Multiplayer

Castle Crashers®
Shared: 2D · Co-op · Action

TEKKEN 7
Shared: Action · Arcade · Controller

Risk of Rain Returns
Shared: 2D · Action · Multiplayer

Windowkill
Shared: Action · Arcade · 2D

METAL SLUG
Shared: Action · Arcade · 2D

Nobody Saves the World
Shared: Action · Co-op · Indie

Overcooked! 2
Shared: Local Co-Op · Co-op · Multiplayer

Timberman
Shared: Action · 2D · Arcade

Shower With Your Dad Simulator 2015: Do You Still Shower With Your Dad
Shared: Arcade · 2D · Action

METAL SLUG X
Shared: Action · Arcade · 2D

METAL SLUG 3
Shared: Arcade · Action · Co-op

Overcooked
Shared: Arcade · Local Co-Op · Co-op

Gang Beasts
Shared: Action · Co-op · Multiplayer

Move or Die
Shared: Action · 2D · Multiplayer

Shank
Shared: Action · 2D · Indie

Rayman® Legends
Shared: Action · 2D · Local Co-Op

Stick Fight: The Game
Shared: Action · Multiplayer · 2D

TowerFall Ascension
Shared: Action · Indie · Local Co-Op