Egg.js is a simple JS library that has no prerequisites and allows you to easily add web easter eggs by watching the user's key strokes. Type the Konami code (up, up, down, down, left, right, left, right, b, a) to test it out. Example It's really easy to use. Just include the egg.js file on the page... <script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/egg.js/1.0/egg.min.js