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Skill v1.0.0

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playableintelligence/game-creator/promo-video
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PublishedSeptember 29, 2026 at 08:48 PM
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version: "1.0.0" name: promo-video description: > Record a high-FPS autonomous promo video of a Phaser game using Playwright. Triggers on: promo video, gameplay recording, marketing video, game capture. argument-hint: "[path-to-game]" license: MIT compatibility: Requires Playwright and FFmpeg installed locally for video capture and encoding. metadata: author: OpusGameLabs version: 1.3.0 tags: [game, promo, video, recording, playwright, ffmpeg]

Promo Video Recording

Record smooth, autonomous promo footage of a Phaser game for marketing / social media. The output is a 50 FPS MP4 in mobile portrait (9:16) — ready for TikTok, Reels, Moltbook, or X.

Technique

Playwright's recordVideo caps at 25 FPS with no config option. We work around it:

  1. Slow the game to 0.5× by patching all 5 Phaser time subsystems
  2. Record for 2× the desired duration at Playwright's native 25 FPS
  3. FFmpeg speed-up 2× → effective 50 FPS output
ParameterDefaultEffect
SLOW_MO_FACTOR0.5Game runs at half speed → 50 FPS output
WALL_CLOCK_DURATIONDESIRED_GAME_DURATION / SLOW_MO_FACTORRecord for 2× to get correct game-time
VIEWPORT{ width: 1080, height: 1920 }9:16 mobile portrait (always default unless user specifies otherwise)
DESIRED_GAME_DURATION13000 (ms)~13s of game-time → ~6.5s promo clip

Prerequisites

  • Playwright — must be installed (npm install -D @playwright/test && npx playwright install chromium)
  • FFmpeg — must be available on PATH (brew install ffmpeg on macOS)
  • Dev server running — game must be served on localhost

Check both before starting:

bash
npx playwright --version
ffmpeg -version | head -1

If FFmpeg is not found, warn the user and skip the promo video step (it's non-blocking — the game still works without it).

Capture Script — Game-Specific Adaptation

Every game gets a custom scripts/capture-promo.mjs. The subagent must read the game's source files to determine:

1. Death/Failure Patching (CRITICAL)

The video must show continuous gameplay — never game over. Read GameScene.js (or equivalent) to find the death/failure method and monkey-patch it out.

How to find it: Search for the method called on collision/death. Common patterns:

  • this.triggerGameOver() — dodge games
  • this.takeDamage() → this.lives <= 0 — multi-life games
  • this.gameOver() — direct call
  • eventBus.emit(Events.PLAYER_HIT) / eventBus.emit(Events.GAME_OVER) — event-driven

Patch template (adapt per game):

js
await page.evaluate(() => {
  const scene = window.__GAME__.scene.getScene("GameScene");
  if (scene) {
    // Patch ALL paths to game over
    scene.triggerGameOver = () => {};
    scene.onPlayerHit = () => {};
    // For multi-life games, also prevent damage:
    // scene.takeDamage = () => {};
    // scene.playerDied = () => {};
  }
});

2. Input Sequence Generation

The video must show dynamic, natural-looking gameplay. Read the game's input handling to determine:

  • Which keys — ArrowLeft/ArrowRight? Space? WASD? Mouse clicks?
  • Input style — continuous hold (movement), tap (jump/shoot), or both?
  • Movement pattern — should the player sweep across the screen, dodge reactively, jump rhythmically?

Input patterns by game type:

Game TypeInput KeysPattern
Side dodgerArrowLeft, ArrowRightAlternating holds (150-600ms) with variable pauses, occasional double-taps
Platformer / FlappySpaceRhythmic taps (80-150ms hold) with variable gaps (200-800ms)
Top-downWASD / ArrowsMixed directional holds, figure-eight patterns
ShooterArrowLeft/Right + SpaceMovement interleaved with rapid fire
Clicker/TapperMouse click / SpaceRapid bursts separated by brief pauses

Randomize timing to avoid robotic-looking movement:

js
const holdMs = 150 + Math.floor(Math.random() * 450);
const pauseMs = 50 + Math.floor(Math.random() * 250);

Add a pause at the start (1-2s) to let the entrance animation play — this is the hook.

3. Game Boot Detection

All Phaser games built with the /viral-game or /make-game pipelines expose these globals:

  • window.__GAME__ — Phaser.Game instance
  • window.__GAME_STATE__ — GameState singleton
  • window.__EVENT_BUS__ — EventBus singleton

Wait for both boot and active gameplay:

js
await page.waitForFunction(() => window.__GAME__?.isBooted, { timeout: 15000 });
await page.waitForFunction(() => window.__GAME_STATE__?.started, {
  timeout: 10000,
});

4. Time Scaling Injection

Slow all 5 Phaser time subsystems for the recording:

js
await page.evaluate(
  ({ factor }) => {
    const game = window.__GAME__;
    const scene = game.scene.getScene("GameScene");
    // 1. Update delta — slows frame-delta-dependent logic
    const originalUpdate = scene.update.bind(scene);
    scene.update = function (time, delta) {
      originalUpdate(time, delta * factor);
    };
    // 2. Tweens — slows all tween animations
    scene.tweens.timeScale = factor;
    // 3. Scene timers — slows scene.time.addEvent() timers
    scene.time.timeScale = factor;
    // 4. Physics — slows Arcade/Matter physics
    // NOTE: Arcade physics timeScale is INVERSE (higher = slower)
    if (scene.physics?.world) {
      scene.physics.world.timeScale = 1 / factor;
    }
    // 5. Animations — slows sprite animation playback
    if (scene.anims) {
      scene.anims.globalTimeScale = factor;
    }
  },
  { factor: SLOW_MO_FACTOR },
);

The 5 subsystems:

  1. Update delta — scene.update(time, delta * factor) slows frame-delta-dependent logic
  2. Tweens — scene.tweens.timeScale slows all tween animations
  3. Scene timers — scene.time.timeScale slows scene.time.addEvent() timers
  4. Physics — scene.physics.world.timeScale slows Arcade/Matter physics (uses inverse: 1/factor)
  5. Animations — scene.anims.globalTimeScale slows sprite animation playback

5. Video Finalization

js
const video = page.video();
await context.close(); // MUST close context to finalize the video file
const videoPath = await video.path();

Full Capture Script Template

js
import { chromium } from "playwright";
import path from "path";
import fs from "fs";
import { fileURLToPath } from "url";
const __dirname = path.dirname(fileURLToPath(import.meta.url));
const PROJECT_DIR = path.resolve(__dirname, "..");
// --- Config ---
const args = process.argv.slice(2);
function getArg(name, fallback) {
  const i = args.indexOf(`--${name}`);
  return i !== -1 && args[i + 1] ? args[i + 1] : fallback;
}
const PORT = getArg("port", "3000");
const GAME_URL = `http://localhost:${PORT}/`;
const VIEWPORT = { width: 1080, height: 1920 }; // 9:16 mobile portrait
const SLOW_MO_FACTOR = 0.5;
const DESIRED_GAME_DURATION = parseInt(getArg("duration", "13000"), 10);
const WALL_CLOCK_DURATION = DESIRED_GAME_DURATION / SLOW_MO_FACTOR;
const OUTPUT_DIR = path.resolve(PROJECT_DIR, getArg("output-dir", "output"));
const OUTPUT_FILE = path.join(OUTPUT_DIR, "promo-raw.webm");
// <ADAPT: Generate game-specific input sequence>
function generateInputSequence(totalMs) {
  const sequence = [];
  let elapsed = 0;
  // Pause for entrance animation
  sequence.push({ key: null, holdMs: 0, pauseMs: 1500 });
  elapsed += 1500;
  // <ADAPT: Replace with game-specific keys and timing>
  const keys = ["ArrowLeft", "ArrowRight"];
  let keyIdx = 0;
  while (elapsed < totalMs) {
    const holdMs = 150 + Math.floor(Math.random() * 450);
    const pauseMs = 50 + Math.floor(Math.random() * 250);
    // Occasional double-tap for variety
    if (Math.random() < 0.15) {
      sequence.push({ key: keys[keyIdx], holdMs: 100, pauseMs: 60 });
      elapsed += 160;
    }
    sequence.push({ key: keys[keyIdx], holdMs, pauseMs });
    elapsed += holdMs + pauseMs;
    // Alternate direction (with occasional same-direction repeats)
    if (Math.random() < 0.75) keyIdx = 1 - keyIdx;
  }
  return sequence;
}
async function captureGameplay() {
  console.log("Capturing promo video...");
  console.log(
    `  URL: ${GAME_URL} | Viewport: ${VIEWPORT.width}x${VIEWPORT.height}`,
  );
  console.log(
    `  Game duration: ${DESIRED_GAME_DURATION}ms | Wall clock: ${WALL_CLOCK_DURATION}ms`,
  );
  fs.mkdirSync(OUTPUT_DIR, { recursive: true });
  const browser = await chromium.launch({ headless: true });
  const context = await browser.newContext({
    viewport: VIEWPORT,
    recordVideo: { dir: OUTPUT_DIR, size: VIEWPORT },
  });
  const page = await context.newPage();
  await page.goto(GAME_URL, { waitUntil: "networkidle" });
  // Wait for game boot + gameplay active
  await page.waitForFunction(() => window.__GAME__?.isBooted, {
    timeout: 15000,
  });
  await page.waitForFunction(() => window.__GAME_STATE__?.started, {
    timeout: 10000,
  });
  await page.waitForTimeout(300);
  console.log("  Game active.");
  // <ADAPT: Patch out death — find the actual methods from GameScene.js>
  await page.evaluate(() => {
    const scene = window.__GAME__.scene.getScene("GameScene");
    if (scene) {
      scene.triggerGameOver = () => {};
      scene.onPlayerHit = () => {};
    }
  });
  console.log("  Death patched.");
  // Slow all 5 Phaser time subsystems
  await page.evaluate(
    ({ factor }) => {
      const game = window.__GAME__;
      const scene = game.scene.getScene("GameScene");
      const originalUpdate = scene.update.bind(scene);
      scene.update = function (time, delta) {
        originalUpdate(time, delta * factor);
      };
      scene.tweens.timeScale = factor;
      scene.time.timeScale = factor;
      if (scene.physics?.world) scene.physics.world.timeScale = 1 / factor;
      if (scene.anims) scene.anims.globalTimeScale = factor;
    },
    { factor: SLOW_MO_FACTOR },
  );
  console.log(`  Slowed to ${SLOW_MO_FACTOR}x.`);
  // Execute input sequence
  const sequence = generateInputSequence(WALL_CLOCK_DURATION);
  console.log(
    `  Playing ${sequence.length} inputs over ${WALL_CLOCK_DURATION}ms...`,
  );
  for (const seg of sequence) {
    if (!seg.key) {
      await page.waitForTimeout(seg.pauseMs);
      continue;
    }
    await page.keyboard.down(seg.key);
    await page.waitForTimeout(seg.holdMs);
    await page.keyboard.up(seg.key);
    if (seg.pauseMs > 0) await page.waitForTimeout(seg.pauseMs);
  }
  console.log("  Input complete.");
  // Finalize video
  const video = page.video();
  await context.close();
  const videoPath = await video.path();
  if (videoPath !== OUTPUT_FILE) {
    fs.renameSync(videoPath, OUTPUT_FILE);
  }
  await browser.close();
  console.log(`  Raw recording: ${OUTPUT_FILE}`);
  console.log("Done.");
}
captureGameplay().catch((err) => {
  console.error("Capture failed:", err);
  process.exit(1);
});

FFmpeg Conversion

After recording, convert the raw slow-mo WebM to a high-FPS MP4. The convert-highfps.sh script is bundled with this skill at skills/promo-video/scripts/convert-highfps.sh.

bash
# Copy to project (orchestrator does this)
cp <plugin-root>/skills/promo-video/scripts/convert-highfps.sh <project-dir>/scripts/
 
# Run conversion
bash scripts/convert-highfps.sh output/promo-raw.webm output/promo.mp4 0.5

The script:

  • Applies setpts to speed up the video by 1/factor
  • Sets output framerate to 25 / factor (= 50 FPS for 0.5× slow-mo)
  • Encodes H.264 with crf 23, yuv420p, faststart
  • Verifies output duration, frame rate, and file size

Viewport Defaults

Always record in mobile portrait (9:16) unless the user explicitly requests otherwise. Rationale:

  • Games are played on phones — promo footage should show the real mobile experience
  • 9:16 is native for TikTok, Instagram Reels, YouTube Shorts
  • 1080×1920 is the standard resolution
Aspect RatioViewportUse Case
9:16 (default)1080 × 1920Mobile portrait — TikTok, Reels, Shorts, Moltbook
1:11080 × 1080Square — Instagram feed, X posts
16:91920 × 1080Landscape — YouTube, trailers, desktop games

Duration Guidelines

Game TypeRecommended DurationWhy
Arcade / dodger10-15sFast action, multiple dodge cycles
Platformer15-20sShow jump timing, level progression
Shooter12-18sShow targeting, enemy waves
Puzzle8-12sShow one solve sequence

Checklist

Before running the capture:

  • [ ] Dev server is running and responding
  • [ ] FFmpeg is installed on the system
  • [ ] Playwright is installed with Chromium
  • [ ] Game boots directly into gameplay (no menu blocking)
  • [ ] Death/failure method identified and patched
  • [ ] Input keys match the game's actual controls
  • [ ] Entrance animation pause is included (1-2s)
  • [ ] Output directory exists

After capture:

  • [ ] Raw WebM exists in output/
  • [ ] FFmpeg conversion produces valid MP4
  • [ ] Duration is ~half the raw recording (speed-up worked)
  • [ ] Frame rate is 50 FPS
  • [ ] Video shows gameplay (not a black screen)
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