90s Retro is a free theme for WordPress created by Organic Themes.
Have you ever wished your WordPress blog looked like an old Geocities site from the 90s.? Probably not. The 90s Retro Theme is designed to look like an old website with pixel fonts, neon colors, background music and animated GIFs mostly because we thought it would be funny. However, it's a great theme for gamers, guilds, video game reviews, collectors, kids and nostalgic adults.
(Description "90s Retro" Theme from wordpress.org)
You can download 90s Retro for free via the provided download link and include it into your themes folder of your WordPress installation. Also you can directly search for it in the WordPress admin interface in the themes section and install and activate it from there.
More information, screenshots and reviews of 90s Retro Theme can be found here.