𝗜𝗻 𝗔𝗿𝗰𝗮𝗱𝗲𝘀 𝗢𝗻 𝗧𝗵𝗶𝘀 𝗗𝗮𝘆 𝟰𝟱 𝗬𝗲𝗮𝗿𝘀 𝗔𝗴𝗼 𝗗𝗘𝗙𝗘𝗡𝗗𝗘𝗥 is a 1981 horizontally scrolling shooter developed and published by Williams Electronics as an arcade video game. It is set on an unnamed planet where the player must defeat waves of invading aliens while protecting astronauts. Development was led by Eugene Jarvis, a pinball programmer at Williams; Defender was Jarvis's first video game project and drew inspiration from Space Invaders and Asteroids. Defender was demonstrated in late 1980 and was released in March 1981. It was distributed in Japan by Taito. Defender was one of the most important titles of the golden age of arcade video games, selling over 55,000 units to become the company's best-selling game and one of the highest-grossing arcade games ever. Praise among critics focused on the game's audio-visuals and gameplay. It is frequently listed as one of Jarvis's best contributions to the video game industry and one of the most difficult video g...