Embedding on another site + the score bridge

Every published game (with embedding on — the default; toggle per game) has a framable embed URL:

<iframe src="https://coolgptgames.com/embed/<slug>" width="100%" height="600"
        style="border:0" allow="autoplay; fullscreen; gamepad"></iframe>

The embedded game forwards score + lifecycle to the host page via postMessage, so a third-party site can show its own leaderboard. Attach the listener before you insert the iframe, and verify the origin:

window.addEventListener("message", (e) => {
  if (e.origin !== "https://coolgptgames.com") return;
  if (e.data?.source !== "coolgptgames") return;
  // { source:"coolgptgames", v:1, type, game, score? }
  switch (e.data.type) {
    case "score":    yourLeaderboard.record(e.data.game, e.data.score); break;
    case "gameover": showPlayAgain(e.data.score); break;
    case "ready": case "gamestart": break; // idempotent lifecycle (may repeat)
  }
});

Any game that calls GameSDK.submitScore / GameSDK.gameOver emits these — no game change needed. Only non-sensitive data crosses (never the player's token). Embedded games play as guests (cross-site storage isolation), so account features — persistent XP, cloud saves, ranked, global leaderboards — only work on coolgptgames.com; local gameplay and the score bridge work anywhere.