Changing map size reloads the game and starts a new city — your autosave is kept, but you will need to generate or load a map at the new size.

The generated layout is streets, zoning, a power plant and parks — every lot starts vacant and the simulation grows it from there.

7% is neutral. Higher rates earn more per citizen but suppress the demand that produces citizens. A year continuously in the red is a bankruptcy.

Utilities and services bill by use, not by existing: a power plant running at a tenth of capacity, or a fire station covering mostly empty land, costs a fraction of its full price. That is why a small town can afford infrastructure it has not grown into yet — and why costs climb as you fill it.

Enact city-wide policies. Each has a monthly cost that scales with population.

Manual disasters strike the centre of your current view. Fire spreads to neighbouring buildings and is contained by fire coverage; bulldozing a burning tile makes a firebreak.

A station only works if its track reaches at least one other station. Track broken by a building in the way counts as two separate lines — check the total above after laying one.

Population thresholds unlock new tools. Locked tools appear dimmed in the build bar.

Seasons tint the ground and lay snow in winter; weather adds rain and snowfall. Both are purely cosmetic — neither changes the simulation.

Every sound is generated in the browser — there are no audio files to download, so it works offline like the rest of the game. The ambient bed tracks your population and quietens at night.

Applies to the app chrome. The city's own day/night cycle runs on the in-game clock, independent of this.

Saves live on this device (IndexedDB) and stay put — nothing is uploaded. Named slots are yours to keep; the autosave slot is overwritten as you play, so park anything you care about in a named slot.

MetroBuild runs entirely in the browser. Nothing is uploaded and no external service is contacted, so there is no API quota to watch.

One tick is one in-game month. Land value, pollution, crime and traffic propagate across the map each month; RCI demand and per-lot growth pressure decide what gets built; the budget prices it all. Terrain and water are Phase 4.