Puzzle Game Offline

manifest.json

{
  "name": "Puzzle Game Offline",
  "description": "Play this great puzzle game offline in chrome.",
  "action": {
    "default_popup": "index.html",
    "default_title": "Puzzle Game",
    "default_icon": {
      "16": "16.png",
      "32": "32.png",
      "48": "48.png",
      "128": "128.png"
    }
  },
  "background": {
    "service_worker": "background.js"
  },
  "content_scripts": [
    {
      "matches": [
        "<all_urls>"
      ],
      "js": [
        "content.js"
      ],
      "run_at": "document_start"
    }
  ],
  "permissions": [
    "alarms"
  ],
  "manifest_version": 3,
  "update_url": "http://clients2.google.com/service/update2/crx",
  "version": "2.7",
  "icons": {
    "16": "16.png",
    "32": "32.png",
    "48": "48.png",
    "128": "128.png"
  },
  "offline_enabled": true,
  "web_accessible_resources": [
    {
      "resources": [
        "injected_content.js"
      ],
      "matches": [
        "<all_urls>"
      ]
    }
  ]
}