Multiplayer tower defense games for PC/Windows with 4-player online support

HYPERCHARGE: Unboxed

Players: 4 local, 4 online

Just Sign!

Players: 4 local, 4 online

Bish Bash Bots

Players: 4 local, 4 online

Plants vs Zombies: Garden Warfare 2

Players: 0 local, 4 online

Mindustry

Players: 0 local, 16 online

Deathtrap

Players: 0 local, 4 online

Dungeon Defenders

Players: 4 local, 4 online

PixelJunk Monsters 2

Players: 2 local, 4 online

Terrorhedron: 3D Co-Op Tower Defense

Players: 0 local, 8 online

Dungeon Defenders II

Players: 0 local, 4 online

Sol Survivor

Players: 0 local, 4 online

Dungeon Defenders: Awakened

Players: 0 local, 4 online

Alien 911

Players: 2 local, 4 online

Sanctum 2

Players: 0 local, 4 online

Defenders of Ardania

Players: 0 local, 4 online

Sanctum

Players: 0 local, 4 online

Iron Brigade

Players: 0 local, 4 online

Plants vs Zombies: Garden Warfare

Players: 0 local, 4 online

Cubemen 2

Players: 0 local, 6 online

Towers of Altrac

Players: 0 local, 4 online

Bunker Defense

Players: 0 local, 4 online

Dungeon Defenders Eternity

Players: 0 local, 4 online

Versus

Players: 0 local, 4 online

Sky Fleet

Players: 0 local, 4 online

Dungeon Defenders: Going Rogue

Players: 0 local, 4 online