Is M.A.S.S. Builder co-op?

Yes, M.A.S.S. Builder supports co-op.

Does M.A.S.S. Builder have PvP?

Steam does not list PvP for M.A.S.S. Builder.

How many people play M.A.S.S. Builder?

About 6 players were in-game when this page was built (2026-09-09).

Ready Up — what game do we play?Compare two Steam libraries →

Multiplayer games › Vehicle combat › Mechs

Is M.A.S.S. Builder multiplayer or co-op?

Yes — co-op. M.A.S.S. Builder is a mechs game released in 2025, 88% positive on Steam (3,869 reviews), with 6 playing right now. $24.99 on Steam.

Co-opSingle-player tooVehicle combat · Mechs

Commander, customize and build your Mechanical Assault Skeleton Suit (M.A.S.S.) and lead the fight against an alien invasion bent on exterminating the human…

Steam tags: Early Access, Action RPG, Mechs, Character Customization, Robots, Gun Customization, Indie, Hack and Slash

Do you and a friend both own M.A.S.S. Builder?

Ready Up compares two Steam libraries and shows every multiplayer game you both have — including whether M.A.S.S. Builder is one of them — then helps you pick tonight's game with a weighted roll or a bracket.

Or open the Steam store page.

Games like M.A.S.S. Builder you can play together

War Robots

Mechs · 60% positive on Steam (26,575 reviews) · 1,280 playing right now

ARMORED CORE™ VI FIRES OF RUBICON™

Mechs · 91% positive on Steam (77,042 reviews) · 1,011 playing right now

Lightyear Frontier

Mechs · 88% positive on Steam (2,490 reviews) · 732 playing right now

MechWarrior 5: Mercenaries

Mechs · 85% positive on Steam (12,756 reviews) · 636 playing right now

The Forever Winter

Mechs · 72% positive on Steam (19,046 reviews) · 379 playing right now

MechWarrior Online™ Legends

Mechs · 80% positive on Steam (12,220 reviews) · 392 playing right now

Tired of M.A.S.S. Builder? The Swap tab finds the closest unowned games of the same type that are newer or rated higher.

Quick answers

Is M.A.S.S. Builder co-op?: Yes, M.A.S.S. Builder supports co-op.
Does M.A.S.S. Builder have PvP?: Steam does not list PvP for M.A.S.S. Builder.
How many people play M.A.S.S. Builder?: About 6 players were in-game when this page was built (2026-09-09).

Ready Up is a free tool: enter two Steam usernames and it lists the multiplayer games you both own, runs a bracket to pick one, and suggests new co-op games that fit how you both play. Ratings, tags and player counts from Steam and SteamSpy; page updated 2026-09-09. Powered by Steam — not affiliated with or endorsed by Valve Corporation or Microsoft. How the data works · Legal & privacy · All types · Game Pass