A Nintendo DS factory game fits a 4.2-million-tile world by storing only your changes
Procedural terrain solves the handheld memory problem until a busy factory needs saving.
A Nintendo DS with 4MB of RAM can host a world containing about 4.2 million tiles, provided the game doesn’t try to keep every tile in memory. Ronan Gaillard’s Factory DS rebuilds the scenery from its coordinates and remembers what the player changed. The factory has outsourced the untouched countryside to mathematics.
Gaillard’s build account supplies a downloadable 1.9MB game for a DS flashcart or an emulator. The project brings factory-building machinery to the old handheld, with terrain generated on demand and separate tables for modified tiles and buildings.
The save file holds differences from the generated world. That makes an enormous map practical, but it doesn’t make saved construction unlimited. The maker measured growing factories and found that around 3,500 buildings could outgrow a 64KB slot. The game builds the new save in memory first and refuses an oversized result, leaving the old one available.
The overflow refusal protects a player’s last working save even after the new factory outgrows its slot. A giant world invites the player to keep building, which makes the eventual save limit particularly unpleasant. Preserving the last good copy doesn’t eliminate the limit, but it stops a full factory from turning into a completely empty afternoon.
The handheld’s constraint makes the difference between world size and player state easy to see. Unchanged terrain is cheap because the same inputs can produce it again. A machine with contents and progress has information the generator can’t reconstruct. Saved state could become the limiting budget as the player makes more of the world their own.
That is a useful way to read the game’s impressive map figure. A big rectangle on a specification sheet doesn’t tell somebody how much they can build, how far they can travel smoothly, or how much survives a restart. Those are separate experiences, even when a launch trailer can fit all of them into one very flattering flyover.
Begin a first session with a small factory and an early save, especially on unfamiliar flashcart hardware. Finding out how the game stores progress is more pleasant before the conveyor belts have claimed the entire evening.
The DS is a good home for this sort of deliberate constraint. The two screens and physical controls give a factory something modern touchscreens don’t automatically provide: a very specific little machine to inhabit. Gaillard says save compression or a warning could follow if somebody pushes far enough; for now, that distant construction challenge remains open.
The factory still has a save limit.