Made of little things.

# Big Rig Rush

![Big Rig Rush: a semi-truck crash on a country road](preview.png)

Top-down driving chaos in a living city, built as a NIP-5D napplet. Pick your
ride, haul cargo across downtown, the hood, the port and the countryside through
day and night, and watch the city's police, fire, ambulance, tow and road crews
clean up every crash you cause. Everything is destructible.

## Rides

1. **Big rig**: an articulated semi with a manual 8-speed gearbox. It can jackknife and roll over.
2. **Sports car**: a light, automatic rear-drive coupe with homing missiles.
3. **Bulldozer**: an armoured tracked dozer that grinds through buildings.
4. **A-10 Warthog**: flies over the city on real A-10C engine and drag numbers, with the
   GAU-8 (1,150 rounds, the 5:1 round mix, recoil), 6 Mk 82 AIR bombs with ballutes,
   a GBU-31 JDAM and 2 Mavericks, and a fighter HUD with bomb pipper and gun cross.
   Here the goal is to leave the city in ruins.

## The map

Ten times the original area: the old city, and across the bay the docks, the
steelworks and refinery, a rail yard, the suburb of Maple Grove, the Strip and its
stadium, Fort Dunmore air base, and a wide backcountry of farms, woods, a reservoir,
a wind farm and the town of Harlan. Everything that stands can be knocked down;
fuel, ammunition and aircraft go up when they do.

## Air raid

Driving the rig, the sports car or the dozer, switch on **A-10 AIR RAID** on the title
sign (or press 5) and a computer-flown A-10 attacks the city around you: power,
water and other infrastructure first, then buildings, Mavericks at the emergency
services and gun runs on the traffic. You can get caught under it. The city's air
defences shoot back; when they bring it down another comes in a while later.

## The city fights back

Bomb it and it reacts like a real city in a disaster. Power stations, substations,
waterworks, water towers, masts and City Hall keep it running: knock them out and
districts black out, traffic lights die, hydrants run dry and the response slows.
Fires spread on the wind and can merge into firestorms. The city evacuates districts
to its shelters, digs survivors out of the rubble, fights the fires from the ground
and the air, calls in mutual aid, and shoots back with anti-aircraft guns and
missiles. A panel in the corner shows how it's holding up.

## Controls

| Key | Action |
| --- | --- |
| 1–4 | Pick a ride on the title sign |
| W / S | Gas / brake (hold S at a standstill to reverse) |
| A / D | Steer |
| N / M | Shift down / up (big rig) |
| Space | Start, or fire missiles |
| H | Horn |
| R | Call your own tow truck |
| F | Call in a favor from the family |
| K / P | Mute / pause |

In the A-10:

| Key | Action |
| --- | --- |
| A / D | Bank |
| W / S, ↑ / ↓ or N / M | Throttle up / back |
| G (hold) | GAU-8 cannon |
| B | Release a bomb (hold to ripple) |
| V | Bomb mode: Mk 82 high drag, low drag, GBU-31 |
| Space | AGM-65 Maverick |
| F | Flares (against missiles) |
| R | Re-arm (and patch up) |

On touch screens the game shows GAS/BRK pedals, steering, shift and weapon pads
(in the A-10: THR+/THR−, GUN, BOMB, FIRE, FLR, WPN and ARM).
Settings for traffic, rude drivers, touch controls, screen shake and volume come
from the host's napplet settings.

## Host capabilities

No domains are required. `storage` (best score) and `config` (settings) are
optional. Without them the game runs on defaults and doesn't save a best score.

## Development

Read [docs/napplet-space.md](docs/napplet-space.md) first for this project's CLI
commands, installed skills, preview cleanup and host capabilities, and
[docs/brief.md](docs/brief.md) for the game's design brief.

```bash
soyli setup        # install dependencies
soyli dev          # hosted preview in the napplet sandbox
pnpm verify        # guidance + type-check + Chromium audio regression tests + build
pnpm test:conformance
```

`soyli build` produces one self-contained `dist/index.html`.

### Listing media

- `preview.png`: the listing cover (1200 × 750), showing a big-rig crash on a country road.
- `preview-audio-improvements.webm`: a refreshed 8 s clip recorded by `soyli record` from the recipe in
  `napplet.json` (`preview.recording`): an A-10 strafes, ripples low-drag Mk 82s and
  banks round over the hits. Re-record it after every build change.
- `icon.png`: the 512 × 512 listing icon, showing the rig.

### Audio mixing

The procedural mix in `src/game/audio.ts` separates driving, background activity,
player effects, impacts and reverb. Impacts duck driving and background activity;
independent event pools bound overlapping crashes, explosions and debris without
using background slots for warnings, delivery cues or the final wreck. Music uses
the two most audible venues. Shorter, quieter reverb reduces buildup, while impact
compression preserves the intentional distorted crunch. A 25 Hz low cut removes
subsonic energy; final compression and a soft peak guard precede user volume, so
lowering volume keeps the same balance. Finished synthesis nodes disconnect after
all scheduled layers finish. Idle gun, jet and fire voices are allocated on demand.

`pnpm test:audio` uses the conformance harness's Chromium and real Web Audio to
render a seeded storm of 1,296 effect requests alongside the jet, gun and fire.
It checks full-scale peaks, silence, bounded source counts, delayed-layer cleanup
and gun crackle during held fire. It is included in `pnpm verify`. These objective
checks do not replace a listening pass for perceived loudness and timbre.

## License

MIT