Multiplayer beat-em-up games for PC/Windows with 2-player online support

Samurai Warriors 5

Players: 2 local, 2 online

Teenage Mutant Ninja Turtles: Shredder's Revenge

Players: 6 local, 6 online

River City Girls 2

Players: 4 local, 4 online

Double Dragon Gaiden: Rise Of The Dragons

Players: 2 local, 2 online

Streets of Rage 4

Players: 4 local, 2 online

Full Metal Furies

Players: 4 local, 4 online

Unending Dusk

Players: 0 local, 4 online

Castle Crashers

Players: 4 local, 4 online

Double Dragon Neon

Players: 0 local, 2 online

Rampage Knights

Players: 2 local, 2 online

Cobalt

Players: 2 local, 8 online

Bravery and Greed

Players: 4 local, 4 online

Sacred Citadel

Players: 3 local, 3 online

Dungeons & Dragons: Chronicles of Mystara

Players: 4 local, 4 online

Double Dragon Trilogy

Players: 2 local, 2 online

River City Ransom: Underground

Players: 4 local, 4 online

Ninjin: Clash of Carrots

Players: 2 local, 2 online

Capcom Beat 'Em Up Bundle

Players: 4 local, 4 online

Shank 2

Players: 2 local, 2 online

Zeno Clash II

Players: 0 local, 2 online

Dungeons: The Eye of Draconus

Players: 3 local, 3 online

Dead Rising 2: Off the Record

Players: 0 local, 2 online

Foul Play

Players: 2 local, 2 online

Elsword

Players: 0 local, 4 online

Zombie Vikings

Players: 4 local, 4 online