The Cross (or X) and Circle buttons are simple enough to decipher — the Circle represents "go" or "ok" (as is its use in Japan) and the Cross represents "no" or "cancel". Comically, Western games have managed to reverse the commands over time.

While said shapes are easy to explain, the Square and Triangle buttons are a little less straight-forward. Thankfully, Japanese designer Teiyu Goto - who designed the original PlayStation, PlayStation 2 and PlayStation 3 - has revealed all in the latest issue of Famitsu.

"Other game companies at the time assigned alphabet letters or colors to the buttons," he said. "We wanted something simple to remember, which is why we went with icons or symbols, and I came up with the triangle-circle-X-square combination immediately afterward. I gave each symbol a meaning and a color.

"The triangle refers to viewpoint; I had it represent one's head or direction and made it green. Square refers to a piece of paper; I had it represent menus or documents and made it pink. The circle and X represent 'yes' or 'no' decision-making and I made them red and blue respectively. People thought those colors were mixed up, and I had to reinforce to management that that's what I wanted."

It's fascinating stuff. We'd love to have been around those initial PlayStation brain-storming sessions. It must have been a really exciting time within Sony. Who knew what success they were about to discover?