Defender, one of the most important arcade games of all time, was released in 1981 by pinball company Williams Electronics and sold around 60,000 units, an unheard-of figure for a video game around that time. Despite its five-button control scheme and challenging difficulty, Defender was a defining feature of the ‘one more go’ feeling that Space Invaders had a decade earlier. Despite a slight growth in 2024, there are currently only around 25 arcade games for legal consideration. However, this makes it a rare sight for gamers to see a retro game in an arcade in 2026. As Defender celebrates its 45th anniversary, this article highlights the importance of preserving this pioneering game.