Games like Massive
Games like Massive include Enter the Gungeon, Risk of Rain 2, Streets of Rogue, Gunfire Reborn, and Vampire Survivors. We matched them by the tags players give Massive on Steam (Action, Indie, Adventure, Action Roguelike, and Multiplayer): closest matches first, and among equally close ones the better-known games.

Enter the Gungeon
Shared: Action Roguelike · Indie · Pixel Graphics

Risk of Rain 2
Shared: Action Roguelike · Action · Co-op

Streets of Rogue
Shared: Action Roguelike · Action · Roguelite

Gunfire Reborn
Shared: Roguelite · Co-op · Indie

Vampire Survivors
Shared: Action Roguelike · Indie · Roguelite

Nuclear Throne
Shared: Action Roguelike · Indie · Action

Left 4 Dead 2
Shared: Co-op · Action · Multiplayer

SYNTHETIK: Legion Rising
Shared: Indie · Action · Action Roguelike

Hero Siege
Shared: Action Roguelike · Pixel Graphics · Multiplayer

Heroes of Hammerwatch
Shared: Action Roguelike · Co-op · Roguelite

Relic Hunters Zero: Remix
Shared: Action · Action Roguelike · Adventure

Ravenswatch
Shared: Action · Action Roguelike · Co-op

Skul: The Hero Slayer
Shared: Action · Indie · Action Roguelike

Wizard of Legend
Shared: Action Roguelike · Action · Pixel Graphics

PEAK
Shared: Adventure · Multiplayer · Co-op

Risk of Rain (2013)
Shared: Indie · Action Roguelike · Action

Broforce
Shared: Action · Co-op · Indie

Hades
Shared: Action Roguelike · Indie · Action

Grand Theft Auto V Legacy
Shared: Action · Multiplayer · Adventure

How to Fish
Shared: Indie · Multiplayer · Co-op

Sephiria
Shared: Action Roguelike · Action · Co-op

Call of Duty®: Black Ops III
Shared: Action · Multiplayer · Co-op

Resident Evil 6
Shared: Action · Co-op · Adventure

Roboquest
Shared: Action Roguelike · Roguelite · Co-op

