developing Hydlide, as he had never used the Apple II before. He said that he only became aware of two other Japanese action RPG projects, Dragon Slayer and Courageous Perseus, while reading a magazine during Hydlides development, and was shocked to find that Hydlide was not the only attempt at the concept. He underestimated Dragon Slayer but felt threatened by Courageous Perseus, believing the latter to be more visually impressive; Courageous Perseus turned out to be not as successful, whereas Dragon Slayer went on to become Hydlides biggest competitor, through subsequent sequels. Reception and legacy Hydlide was well-received and considered an innovator when released in Japan in 1984. Hydlide was one of the first action role-playing games, along with Courageous Perseus and Dragon Slayer. Hydlide was also an early open world game, rewarding exploration in an open world environment. It also had the ability to switch between attack mode and defense mode, quick save and load options which can be used at any moment of the game, and the introduction of a health regeneration mechanic where health slowly regenerates when standing still. It sold 2 million copies in Japan, including 1 million for home computers (including the PC-88, PC-98, PC-66, Sharp X1, FM7, MSX, MSX2, and MZ-2000) and 1 million for the Famicom console. It was the first computer game to receive a Platinum award from Toshiba EMI for a million sales. However, it failed to capture the same attention beyond Japan. The game was influential on the action RPG genre, including titles such as Ys. For example, Ys uses a similar health-regeneration mechanic. The recharging health mechanic first introduced by Hydlide in 1984 would, decades later, become a common mechanic widely used in many video games, including shooter games such as Halo. Hydlides open world game design inspired Hideo Kojima, who designed Metal Gear Solid V: The Phantom Pain so that it captures the open-world feel he felt when he first played Hydlide on PC. PlatinumGames director Hideki Kamiya was inspired by the Hydlide series, which he cited as an influence on Scalebound, a cancelled open world action RPG. Hydlide was initially released outside of Japan through the European release of the MSX version. Beyond that, 1989 saw the release of a localization of Hydlide Special for the NES, simply titled Hydlide itself. Unlike Dragon Quest, which was improved upon for its US localization, Hydlide was left essentially unaltered