This plugin for WordPress adds a number of retro space invaders to your blog pages
that will randomly fly around, and if you choose home in on any mouse clicks.
You can choose the number, size, speed, and behaviour of the space invaders as
well as limit them to a specific area of your pages, a single post, or the entire
blog.
Great glowing retro 8bit scanline effect space invaders work on most backgrounds
but obviously are more suited to a dark theme.
Demo
You can see them in action on the plugin page at
http://strawberryjellyfish.com/wordpress-plugin-jellyfish-invaders/
This plugin uses the excellent Spritely library for jQuery. Read more about
Spritely at
http://www.spritely.net/
Extract the zip file and just drop the contents in the wp-content/plugins/
directory of your WordPress installation and then activate the Plugin from
Plugins page. Visit your blog and marvel at the spectacle, then go to the
Jellyfish Invaders settings page in the Appearance menu of your WordPress
admin to play with the settings.