If you read my recent article on the 9 most difficult PlayStation 1 levels of all time, then you might be in agreement with me when I say that for all the pain and misery that it might have caused, the PlayStation will remain very close to the centre of the hearts of an entire generation.

The original PlayStation is probably the most important console ever made because it revolutionised how games are played. It was the first mainstream console to implement memory cards and CD-ROMS, just to name two things, and it gave us some of the best games of all time.

The PlayStation was first released in December of 1994 and was officially discontinued in March of 2005. In that time – just over ten-and-a-half years – it sold 102 million units. To put that into context, that’s more than the PlayStation 3, which sold 80 million units, more than the Xbox 360, which sold 84 million units, and only 18 million units less than every Game Boy console put together.

The point I’m making is that the PlayStation was a game changer (pun very much intended) when it was first released, and created a legacy as not only one of the most important consoles of all time, but also one of the most revolutionary.

One small way it revolutionised gaming is something many of you have perhaps not even considered, which is that before the PlayStation, the only way to distinguish buttons on a controller was by letters. The PlayStation was the one of the first console to use shapes – and certainly the first to get it right. It may not seem like much, but the reason behind it will blow your mind.

One might think that the shapes were picked arbitrarily, but that could not be further from the truth. Instead, careful consideration and thought went into what shapes should be used, and what colours should be used for those shapes. Moreover, a great deal of thought went into which shapes should correspond to which command during gameplay.

In a recent interview with 1up, Sony designer Teiyu Goto spilled the beans as to what he had in mind with each button, and when you hear what he said, it will all make so much more sense:

“Other game companies at the time assigned alphabet letters or colors to the buttons. 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 colour. 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.”

Interestingly enough, at least one controller contemporary to the PlayStation also had shapes for buttons: The Apple Bandai Pipp!in, designed by Apple and produced by Bandai in 1995. But as the old saying goes, it doesn’t matter who thought of the idea first, all that matters is who did it best. The Bandai Pipp!in sold extremely poorly. It cost $599, which was outrageously overpriced for what it was, and it was discontinued a year later.

It also had the dubious honour of placing on PC World’s 25 Worst Tech Products of All Time list; not exactly a PlayStation, by more metrics than one.