Gekkó is a fictional government agency, also known as the Department of Super Secret Affairs. You play the role of a Gekkó agent and help your friends and colleagues to deal with various tasks.
Some tasks are about hacking, but Gekkó is not a CTF in the classic sense. When I created it at the beginning of the 2000s, I wanted to come up with something extraordinary, that makes it distinct from the many challenge sites of the era.
There were dozens if not hundreds of sites with vibrant communities. I consider it as the golden age with wechall being a meta site collecting most of them. A lot of us grew up playing these games, got hooked and started their own sites using .php and picked up things during the way. We knew nothing at the beginning for sure, but fellow challengers later became pentesters or made carieers as security experts at big companies.
* To protect your privacy, your email is not stored in plaintext form, and it is used only for password reset.