Examine source code of Boxel 3D

{
  "action": {
    "default_popup": "index.html",
    "default_title": "Boxel 3D"
  },
  "description": "Boxel 3D is the 3rd release of your favorite box jumping game made by the developers of Boxel Rebound.",
  "differential_fingerprint": "1.122bbae6913f598f3f740bc4a6bd76b1ae6eca15357660f90268484564e3d49f",
  "icons": {
    "16": "img/png/icon16.png",
    "48": "img/png/icon48.png",
    "128": "img/png/icon128.png"
  },
  "key": "MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAhMTfULqpeJHWuNK+laOMiTaDWPoU7vKt6lK77peNX7duvLy5souC8IowS+YbywdWyEr3880DtEM9szyOkBDIl3b0l67nNtQxWrZiWPbjKrDsHcIU7aE9Q/Vp0gEdrAje7Ip+4FJVb6jAv4k0KOLuZCODV3QPK6eoQl3LxmbqkvuCY7HH+5EM95mBk+uZzC5erCzn7O8rIHOYzt09jAecw3r73xL22n/LCONTUcaWTacYivKGeLL2+4N+UJ7ZfzR9FZxRnquznXjju+NEDbs9+rVMMUpJalSJgJ3GbvlFx+i966rMN2Z7FRhKW6Yx4JacQcRi0jU5XkXTgBrtUdhJgQIDAQAB",
  "manifest_version": 2,
  "name": "Boxel 3D",
  "permissions": [
    "storage"
  ],
  "update_url": "https://clients2.google.com/service/update2/crx",
  "version": "1.1.9.4",
  "browser_specific_settings": {
    "gecko": {
      "id": "{c7c8d2a6-d3e7-4da0-bdee-d6830a326872}"
    }
  }
}