Thexder was an important breakthrough title for the run-and-gun shooter game genre, paving the way for titles such as Contra and Metal Slug. The game went on to sell over one million copies worldwide, becoming one of the best-selling computer games up until that time.In the game, the player is a fighter robot, but is able to transform into a jet. Originally released in 1985 for the NEC PC-8801 platform in Japan, the game quickly became a best-selling hit selling over 500,000 copies.[3] Later that same year, Game Arts licensed Thexder to Square in order to develop a conversion for the Nintendo Entertainment System (NES) game console. In 1987, Game Arts also developed a Thexder conversion for the MSX platform.