Moon Sweepers Multiplayer Guide: Max Players, Shared Upgrades, Public Lobbies and How to Kick Griefers

Moon Sweepers is the surprise co-op hit of the autumn: a game about cleaning the entire Moon, starting with nothing but a toothbrush. Just one week after its October 23, 2026 launch, developer DragDrop Games counted 600,000 players and a peak of 70,000 concurrent players. Most of them are doing it together, which is why Moon Sweepers multiplayer questions are everywhere right now. How many players fit into one crew? Are upgrades shared? And what can you do when a stranger joins your public game and tears down your base? This guide answers all of it, based on the official patch notes up to version 1.0.5.

Moon Sweepers Multiplayer: How Many Players Can Join?

Moon Sweepers supports online co-op for up to 16 players in one crew. You can spread out to cover more ground or all work on the same area, and you can also play the whole game solo if you prefer. The game is made by a team of just two developers, so the multiplayer side has changed a lot through quick patches in the first week. Everything below reflects those changes.

• Max players: 16 in one online co-op session.
• Solo: Fully supported, no friends required.
• Platform: Windows PC via Steam only. There is no PlayStation, Xbox or Switch version, so there is no console crossplay either.
• Achievement: Starting a game with at least one friend unlocks “OH You Have Friends?”.

How to Play Moon Sweepers With Friends

Co-op in Moon Sweepers runs through Steam, and the session always lives on the host’s save. That matters, because the host’s world, the host’s upgrades and the host’s ban list are what everybody plays with.

1. Update first. Everyone in the crew needs the same game version. The developers spelled this out with Patch 1.0.3, so if a friend can’t join, check for a pending Steam update before anything else.
2. Pick one host. The host starts a new Moon or loads an existing save. Use the same host every time if you want to continue the same world.
3. Choose who can join. Players report that crews can be set to public or restricted to friends or invites. Since Patch 1.0.5, the game asks for confirmation before you start a public game or switch your crew to public.
4. Invite your friends through Steam. Your friends accept the invite and load into the host’s Moon.

Are Upgrades Shared in Moon Sweepers Co-op?

Yes, at least for the upgrade matrix. At launch, upgrades were not shared across the crew. Patch 1.0.3 changed that: the whole crew now uses the host’s upgrade matrix, and any crewmate’s purchase upgrades everyone. If you are coming back to an older save, the game kept the highest level that anyone in the crew had already bought.

Vehicles are handled through garages. Since Patch 1.0.3, your vehicles work at every garage, so any garage can call them back, store them and upgrade them. Demolishing a garage also no longer deletes the vehicles kept there; they move to another garage or wait for the next one you build.

With up to 16 players in one crew, the stations get busy fast.

Public Lobbies and Griefers: How to Kick or Ban Players

Public games are a great way to find helpers, but in the first week several players on the Steam forums reported strangers joining and tearing down their bases. The developers have since added proper host tools:

• Kick and ban: Open the ESC menu and go to YOUR CREW. It lists everyone in the session, and the host can kick or ban any player there.
• Bans stick to the save: A banned player can’t join that save again. The host can lift the ban in the same menu.
• Public game warning: Since Patch 1.0.5, starting a public game or switching to public shows a warning that explains what other players can do to your Moon and how to kick or ban them.
• Restrict access: If you only want people you know, keep your crew off public. A few players report that their friends could still join an invite-only crew without an invite, so test your setting with a friend before you leave a big base unattended.

Your Safety Net: Automatic Save Backups

Since Patch 1.0.4, Moon Sweepers keeps up to 5 full backups of your world per save slot. The first one is taken a minute into every session, and then one every 30 minutes. They are stored outside Steam Cloud, in this folder:

C:\Users\[user-name]\AppData\LocalLow\DragDropGames\MoonSweepers\Backups

If a save is damaged, the game restores it from these backups automatically when the world loads and tells you about it. After a crash, it also checks and repairs your save files on the next start. The developers have not published a step-by-step guide for rolling back a save by hand, so if griefers or a bug wrecked your base, copy the Backups folder somewhere safe first and ask in the official Moon Sweepers Discord before you overwrite anything. One more note: saves made in 1.0.4 or later can’t be opened in older versions of the game.

Moon Sweepers Co-op Tips for Your Crew

• Split the jobs. Collecting dust, delivering it to a depot and launching shipments all compete for your time. In a group, let one player clean while another handles deliveries and a third builds conveyor belts and machines.
• Build on each other’s belts. Since Patch 1.0.4, any crewmate can place splitters and mergers on belts built by other players, and mergers now alternate between their inputs.
• Everyone sees the same Moon. Patch 1.0.4 reworked ground synchronization, so cleaned ground, robot trails and manual cleaning now look the same for every player and dust no longer reappears.
• Let J.O.O.N.A.S. work while you are away. Since Patch 1.0.4, the J.O.O.N.A.S. cleaning robot keeps working even when no players are nearby, so your crew can spread out across the Moon.
• Rebuilding is free. Since Patch 1.0.5, removing a piece refunds its whole price instead of 75%, and Move Mode (press R with the building tool) lets you pick up a piece with everything standing on it and place it again for free.
• Adjust the chat voice. The text chat is read out by text-to-speech. Patch 1.0.5 added a Chat voice slider under Settings, Audio.

Shared belt building makes big co-op factories much easier to plan.

Moon Sweepers Multiplayer: Our Verdict

Moon Sweepers multiplayer is at its best with a trusted crew: up to 16 players, one host whose save and upgrade matrix everyone shares, and kick and ban tools in the ESC menu if a public game goes wrong. Keep everyone on the same version and remember that your backups are waiting in the LocalLow folder. DragDrop Games has already announced Update 1.1 for December 2026 with new machines, production chains and more automation, so expect more to build together soon. Looking for another co-op game where the details matter? Read our How to Fish multiplayer guide. This guide reflects Moon Sweepers version 1.0.5 (October 2026), and options may change with future patches.

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Picture Source: DragDrop Games