Build Germany’s railway network in real time.
Version 1.0.0 · 30.08.2026 · ViezTrinker · Repository
Cities appear on a schematic map of Germany at their real coordinates. You draw lines, buy trains, and keep passengers moving — while track costs, maintenance, and platform patience try to ruin your day.
Inspired by the spirit of Mini Metro, but grounded in German geography and a gravity-based demand model: Berlin pulls more trips than a 12,000-person town.
See CHANGELOG.md for release notes.
- Real German cities — places with 10,000+ inhabitants, matched to nearby stations (GeoNames-derived catalog)
- Live trains & passengers — shuttles run in simulation time; passengers pick routes with expected waits and transfers
- Gravity destinations — large cities attract more traffic; optional destination “events” spike demand
- Economic mode — pay for track and trains, earn fares, manage maintenance (Sandbox available for free play)
- Lose conditions — bankruptcy after sustained negative balance, or platforms that wait too long (patience)
- Play session logs — JSONL dumps next to the executable for balance tuning
Deep dives live under doc/.
| CMake | 3.24+ |
| Compiler | C++20 (MSVC recommended on Windows) |
| Other | Git; network on first configure (SFML, GoogleTest, nlohmann/json are fetched automatically) |
cmake -S . -B build
cmake --build build --config ReleaseRun tests:
ctest --test-dir build -C Release --output-on-failure| Generator | Executable |
|---|---|
| Multi-config (Visual Studio) | build/bin/Release/MiniDB.exe |
| Single-config (Ninja, etc.) | build/bin/MiniDB / MiniDB.exe |
data/ is copied next to the binary. Start the game, open Settings, then Start.
- Cities unlock over time (faster in Sandbox).
- Click stations to draft a line → Enter / right-click to confirm (first train is included).
- Extend lines with terminus handles, insert stations by dragging a line onto a city, drop the train token to add capacity.
- Keep cash non-negative and platforms from overflowing — or enable Never lose / Sandbox in Settings.
Escape returns to the menu without wiping the run (Resume continues it).
| Input | Action |
|---|---|
| Left-click station | Inspect / draft |
| Enter / right-click | Confirm line |
| Drag terminus / line | Extend / insert station |
| Train token → line | Add a train |
| Del | Delete selected line |
| Ctrl+Z / Ctrl+Y | Undo / redo draft |
| Space | Pause |
1 2 4 8 / bottom bar |
Speed (up to 16×) |
Wheel / + - |
Zoom |
| Arrows / middle-drag | Pan |
| F11 | Fullscreen |
? |
In-game help |
Unless Sandbox is on:
- Starting balance scales with train capacity (€500,000 at capacity 160).
- Unique track pairs cost to build; shared segments are free after the first build.
- New lines must afford track + first train.
- Trains have purchase and per-second maintenance costs; passengers pay fare by beeline distance.
- Cities unlock every 45 sim seconds in economic mode (every 5 s in Sandbox); spawn pressure rises with unlocks.
- Crowded platforms add dwell time.
| Condition | Rule |
|---|---|
| Bankruptcy | Balance stays negative for 5 minutes of real time (pause freezes the timer) |
| Platform patience | After 20 sim minutes of grace: 360 s wait on a connected platform, or 900 s if the station is still unconnected |
Never lose keeps economy numbers running but disables both lose conditions.
Economic sessions write logs/play_YYYYMMDD_HHMMSS.jsonl beside the executable.
- C++20 simulation core (
MiniDbCore) + SFML 3 UI - Headless-friendly world APIs and GoogleTest coverage
- Station catalog + Germany outline as static JSON/GeoJSON (
data/DATA_SOURCES.md)
Regenerate station data (optional):
python tools/generate_station_data.py- Regional vs long-distance train classes or fares
- Multiple stations per city
- Real railway geometry / timetable speeds
- Spectator AI (experimental work lives on other branches)
MiniDB source code and documentation are licensed under the MIT License.
Bundled station and outline data keep their own terms — see data/DATA_SOURCES.md (GeoNames CC BY 4.0, Germany outline via isellsoap/deutschlandGeoJSON / BKG-derived data).