Heheh, it's Mozilla being cheerfully quirky on the Firefox page (you are talking about the Mozilla Firefox Start Page or "about:home", right?).

If so, Mozilla will be changing it with another image in the future; I don't know when, though. For now, you have a few options:

• Set Google/Bing/etc. as your homepage so that you won't see the Start Page when Firefox launches.
• Use the Stylish extension to remove the image.

Using the Stylish Addon:

1. Click the Stylish icon > Write new Style > For this URL (as seen in the first image below)
2. Create a style as seen in the second image (you can name it whatever you'd like, but
   #brandLogo {
  visibility: hidden;
}
   must be kept. This makes the arcade game invisible. If you'd like to remove it altogether, swap visibility:hidden; with display:none;.

Save your style. A few weeks later, you can check to see if the arcade game has been removed by Mozilla by disabling the Stylish style on the Start Page. I know it's not a straightforward fix, but it's the best I can do.  :)

I hope that helped you! If it did, please mark this answer as the solution so that others can find information on the forums quickly. Thanks! And of course, please post back if you need more help.

Happy browsing!

If you prefer not to see snippets on the about:home page then you can set the browser.aboutHomeSnippets.updateUrl pref to an empty string on the about:config page. Delete the storage\moz-safe-about+home folder in the Firefox profile folder with Firefox closed to remove snippets stored in IndexedDB and make Firefox use a default set.

You can use this button to go to the currently used Firefox profile folder:

• Help > Troubleshooting Information > Profile Directory: Show Folder (Linux: Open Directory; Mac: Show in Finder)

You can reset the browser.aboutHomeSnippets.updateUrl pref if you want to see the snippets again.