Sandustry Custom Maps

That is an unsatisfying answer, so here is the evidence behind it rather than a workaround that does not exist.

The two catalogues, and who can reach them

Sandustry’s Steam Workshop calls itself “Mods and maps for Sandustry”, and it does carry mods — 34 items when this page was checked on 17 August 2026. It carries no maps at all.

Fluxloader, the community loader, lists 41 items tagged as maps out of about 100 in total. But Fluxloader attaches only to a demo install: it goes looking for one and stops when it cannot find it. Everything built on top of it inherits that, including the Custom Map Loader.

So the map catalogue and the released game do not currently meet. If you want to play these maps, the free demo is the only way to, and it is a 2025 build that plays differently from what you bought.

Installing one on the demo

Three steps, in this order:

1. Install Fluxloader. Download the latest release from the project’s GitHub, run it, and let it find your game. The mod loader page covers this and what it grants a mod once it is running.
2. Install the Custom Map Loader from inside the Fluxloader app — it is item 4.1.6, by Electric131. Its README is explicit that Fluxloader has to be there first.
3. Install the maps themselves the same way, from the same catalogue.

Restart the game and your maps are in a dropdown on the main menu. If that dropdown misbehaves, the same selection exists in the Custom Map Loader’s config inside the Fluxloader app.

A map is terrain, so saves do not move between them

This is the part that costs people a factory.

A custom map replaces the world your save was built in. Loading an existing save against a different map — or against a different version of the same map — gives you a save whose buildings were placed against terrain that is no longer there.

The Custom Map Loader is documented as warning you when you try it, and that warning is worth having, because 35 of the 41 maps have shipped a version past 1.0.0 — “the same map” is not a stable thing over time.

Start a new save for a new map, and back up before you change anything — where Sandustry saves your game has the paths.

What is in the catalogue

Forty-one of them, and the names give you the range better than any grouping this page could invent: Volcanic Sands, Underwater Caves, Abandoned Facility, Arcane Ruins, Lakeside Sunset, Volcano Island, The Overhang, Procedural Challenge, Digging Madness, Prison Escape!, The Divider, Pixel Perfect!, InfiniMines, Smaller Caves, Titan X, Asteroid, Abyss, Ode to Mario, GOATLANDIA, Screenshot Saturday.

Read each map’s own description in the catalogue before installing it — this page does not categorise them, because the titles mislead. Digging Madness, for one, says outright that it contains no challenges.

One tag beyond map appears anywhere in the catalogue: unlimitedwater, on Old World Cistern, which tells you what that map changed about the resource everything else depends on.

Shinaidra is credited on the most maps — 11 authored alone, 13 including collaborations. Several entries name co-authors in the author field, which is a fair signal of how small and connected this scene currently is.

Making one

The Custom Map Loader’s wiki documents the whole path, and the workflow is short. Note that what you build targets the demo ecosystem, since that is where the loader runs:

1. Create a mod folder — from an existing mod as a template, or with Fluxloader’s Create Mod button.
2. Configure modinfo.json. The map tag is required, and the Custom Map Loader has to be listed as a dependency. The wiki recommends the "^x.x.x" caret form for that dependency, but it is a recommendation rather than the only accepted syntax — the catalogue contains entries pinned as >=4.1.2. Any other mod you used while building goes in as a dependency too.
3. Build the map PNGs and the files beside them. A map is images plus metadata plus, optionally, scripting.
4. Load it in game to check the configuration took.
5. Zip the mod folder and upload it to the Fluxloader site.

The one requirement the wiki calls out by itself is the tag:

CommunityEnsure your map modinfo.json file has the map tag (otherwise the CML won’t recognize it)

Miss it and nothing is broken and nothing appears — the loader simply does not see your map.

The wiki’s own pages cover the details this page does not: the PNG layers, the colour mapping, the metadata format and map scripting. It states it is current as of version 4.1.3, while the loader itself is on 4.1.6, so expect the documentation to trail the tool slightly.

Before you start

Fluxloader, the Custom Map Loader and every map on it are community software, unaffiliated with Lantto Games or Hooded Horse. Neither loader project publishes a licence file.

Anything a modded world tells you about mechanics may not hold in an unmodded one — including the figures elsewhere on this site, which are measured against the unmodified game.

Related

• Sandustry Mod Loader — which loader your version can use, and for what
• Sandustry Demo vs Early Access — what else separates the two builds
• Sandustry Maps and Exploration — the generated world you get without any of this
• Where Sandustry Saves Your Game — back these up first