Games like PopSlinger
Games like PopSlinger include Muse Dash, Streets of Rage 4, METAL SLUG, Alex Jones: NWO Wars, and Guns, Gore & Cannoli. We matched them by the tags players give PopSlinger on Steam (Side Scroller, Shoot 'Em Up, Beat 'em up, Puzzle, and Rhythm): closest matches first, and among equally close ones the better-known games.

Muse Dash
Shared: Rhythm · Female Protagonist · Cute

Streets of Rage 4
Shared: Beat 'em up · Side Scroller · Arcade

METAL SLUG
Shared: Side Scroller · Shoot 'Em Up · Arcade

Alex Jones: NWO Wars
Shared: Shoot 'Em Up · Side Scroller · Shooter

Guns, Gore & Cannoli
Shared: Side Scroller · Shoot 'Em Up · 2D

Huntdown
Shared: Side Scroller · Shoot 'Em Up · Shooter

Nitro Express
Shared: Side Scroller · Beat 'em up · Shooter

Teenage Mutant Ninja Turtles: Shredder's Revenge
Shared: Beat 'em up · Side Scroller · Arcade

DRAINUS
Shared: Shoot 'Em Up · Shooter · Side Scroller

Phantom Breaker: Battle Grounds Classic
Shared: Beat 'em up · Side Scroller · Female Protagonist

Hitler is my crush
Shared: Side Scroller · Shoot 'Em Up · Shooter

Bit Blaster XL
Shared: Shoot 'Em Up · Shooter · Arcade

Mirage Feathers
Shared: Shoot 'Em Up · Shooter · Cute

The Vagrant
Shared: Side Scroller · Female Protagonist · 2D

Fight'N Rage
Shared: Beat 'em up · 2D · Arcade

METAL SLUG 3
Shared: Side Scroller · Arcade · Shooter

ICEY
Shared: Side Scroller · Female Protagonist · Action

Kero Blaster
Shared: Side Scroller · Shoot 'Em Up · Shooter

Deathsmiles
Shared: Shoot 'Em Up · Arcade · Side Scroller

Hatsune Miku: Project DIVA Mega Mix+
Shared: Rhythm · Arcade · Cute

Beat Hazard
Shared: Rhythm · Shoot 'Em Up · 2D

Kung Fury: Street Rage - Ultimate Edition
Shared: Beat 'em up · Side Scroller · Arcade

Geometry Dash
Shared: Rhythm · 2D · Side Scroller

Broforce
Shared: Side Scroller · 2D · Shooter