Friends and server size
The description says clean with up to 4 friends. The same public page lists server size 20. Do not treat 20 as the co-op cap or 4 as the whole server.
Shared things described in pass and bay wording:
- A vehicle in a shared bay can be driven by the crew on that Moon.
- Head Start's walk-behind sweeper is shared, and only appears if a bay is empty.
- A robot dock's robots are described as cleaning for the whole crew.
- 2x Cash is described as boosting the owner's hand, driving, tile, and automation share. It does not say it copies the pass onto friends.
Split the work if the tools are on screen: one player finishes a tile, another dumps or places the next belt. Two people on one tile clear corners faster than two people crossing the same clean ground.
Tiles
Work outward from the base. A November 9 walkthrough says a finished tile pays more cash than unfinished sweeping. A later walkthrough adds an estimated 3 to 4 Shards and says the meter can finish around 95%. Those Shard and percent figures are not on the listing. If your meter still wants the last specks, clean them. If it completes early, move to the next tile.
100% clean
The goal line is to get the Moon to 100% clean, one tile at a time. The public page does not say whether that percent is yours, your crew's, or the server's, and it does not describe a rebirth or a reset after 100%. Spotless is only the first tile. Dust Devil is 1,000 kg across moons, which is a weight total, not the same as 100%.
Until you can see a clean meter, keep dumping and finishing tiles. Vehicles and robots scale that same job. They are not a separate win condition.