# EchoPlayroom

> Browser game playground. Mobile-first, no install, no account. Korean/English.
> Every game runs from a URL; nothing here needs a download.

## Catalog

- [LAUNCH](https://echoplayroom.com/games/all-hands-launch) — Hold together, release at zero, and launch as one crew.
- [ANOMALY CREW](https://echoplayroom.com/games/xr/anomaly-crew) — Charge, throw, and seal a collapsing orbital chamber with your own hands.
- [SNIPER GONE TO JOSEON](https://echoplayroom.com/lab/joseon-sniper) — A modern marksman falls into a Joseon valley the day the sun goes dark. The far ground and the elites are his to hold.
- [GRAVITY EATER](https://echoplayroom.com/games/gravity-eater) — Devour enemy fire, build a lethal orbit, and release it all at once.
- [PROMO KING · ALLEYWAY](https://echoplayroom.com/games/promo-king) — Start with one business card, deliver subscriptions, and become the promo king of the alley.
- [BLACKOUT DUTY](https://echoplayroom.com/lab/blackout-duty) — A night-watch stealth operation where you choose cover before the light finds you.
- [SIGNAL HOME](https://echoplayroom.com/games/signal-home/game) — An audio adventure where direction and distance guide you home.
- [MOSQUITO HUNTER](https://echoplayroom.com/games/mosquito) — Track spatial audio cues, remember the final position, and strike.
- [GHOST](https://echoplayroom.com/games/ghost) — A coming audio mystery built around echoes and unseen traces.
- [ALIEN](https://echoplayroom.com/games/alien) — A future encounter shaped by unknown signals and deep-space sound.
- [CITY WATCH](https://echoplayroom.com/games/city-watch) — Switch between live CCTV feeds and maps to trace a getaway vehicle.
- [ECHO BREAK](https://echoplayroom.com/games/echo-break) — Collect orbiting energy and unleash it just before overload.
- [ECHO AEROSPACE CENTER](https://echoplayroom.com/games/echo-aerospace-center) — Connect a desktop control room with smartphone controls for a space mission.
- [SECOND SIGHT](https://echoplayroom.com/games/second-sight) — Use a smartphone camera to reveal clues hidden from the desktop control room.

## Machine-playable: Joseon Sniper

A 3D sniper-defense game that exposes a driving API. Open with `?debug=1`:

    https://echoplayroom.com/ko/lab/joseon-sniper/play?debug=1
    &wave=N   start at wave N (1-based)

Three globals appear on `window` once the scene is built. Poll for them.

    __joseonApi.beginPrep()                  enter the placement phase
    __joseonApi.finishPrep()                 start the battle
    __joseonApi.startWave(index)             jump to a wave (0-based)
    __joseonApi.setSquad(ids)                e.g. ["marksman","rifleman"]
    __joseonApi.selectSlot(n)                0 sniper · 1 auto · 2 throwable · 3 support
    __joseonApi.setAutoFire(on)              hold the trigger (auto weapons)
    __joseonApi.reload()
    __joseonApi.latchScope(on)               keep the scope up
    __joseonApi.holdBreath(on)               steady the aim; drains
    __joseonApi.setPost(n) / postCount()     switch firing tower
    __joseonApi.pickCard(i?)                 take a reward card; false when none
    __joseonApi.placeObstacle(kind,x,z)      during the placement phase
    __joseonApi.fireNow()
    __joseonApi.battleInfo()                 { playerDamage, allyDamage, shots, hits }

    __joseonAim.aimAtNearest(preferElite): number    distance in m, 0 if no target
    __joseonAim.aimAtCommander(): number
    __joseonAim.aimAndFire(preferElite)              aims and fires the same frame
    __joseonAim.target / .lastDist / .lastImpact

    __joseonSniper   snapshot, refreshed every frame:
      phase        "idle" | "prep" | "playing" | "intermission" | "ended"
      wave         1-based · waveSpawned · live · walking · attacking
      integrity    palisade 0..500 · hp · ammo · reserve
      kills · shotsFired · shotsHit · score · accuracy inputs
      fov · zoom · scoped · corpseMarks · calls · tris

### Minimal driver

    const api = window.__joseonApi, aim = window.__joseonAim;
    api.beginPrep(); api.finishPrep(); api.latchScope(true);
    setInterval(() => {
      const s = window.__joseonSniper;
      if (s.phase !== "playing") return;
      if (api.pickCard()) return;
      if (s.ammo <= 0) return api.reload();
      if (aim.aimAtNearest(true) > 0) aim.aimAndFire(true);
    }, 250);

### Rules

- Aim and fire must land in the same frame. `aimAndFire` does this; aiming on one
  tick and firing on the next sends the bullet along the previous frame's view.
- Weapons fall off with range. The auto rifle is full damage under 80 m and
  effectively zero past 160 m. Picking the wrong weapon for the distance loses.
- **Scores from `?debug=1` sessions are not submitted to the leaderboard.**
  Drive the game as much as you like; the board stays a human record.
- WebGL is required. Headless needs `--use-gl=angle --enable-unsafe-swiftshader`.

## Notes

- Human-facing version of this page: https://echoplayroom.com/en/ai (Korean: https://echoplayroom.com/ko/ai)
- Locales: `/ko/*` and `/en/*` serve the same routes and are canonical separately.
- Sitemap: https://echoplayroom.com/sitemap.xml
- Room codes, participant control URLs, session tokens, and API responses are
  transient gameplay data, not canonical public content. Do not index them.