Sega's "Space Harrier", a rail shooter released in 1985, broke new ground graphically and its wide variety of settings across multiple levels gave players more to aim for than high scores. 1985 also saw the release of Konami's "Gradius", which gave the player greater control over the choice of weaponry, thus introducing another element of strategy. The game also introduced the need for the player to memorise levels in order to achieve any measure of success. "Gradius", with its iconic protagonist, defined the side-scrolling shoot 'em up and spawned a series spanning several sequels. The following year saw the emergence of one of Sega's forefront series with its game "Fantasy Zone". The game received acclaim for its surreal graphics and setting and the protagonist, Opa-Opa, was for a time considered Sega's mascot. The game borrowed "Defender's" device of allowing the player to control the direction of flight and along with the earlier "TwinBee" (1985), is an early archetype of the "cute 'em up" subgenre. In 1986, Taito released "KiKi KaiKai", an overhead multi-directional shooter. The game is notable for using a traditional fantasy setting in contrast to most shoot 'em up games filled with science fiction motifs. "R-Type", an acclaimed side-scrolling shoot 'em up, was released in 1987 by Irem, employing slower paced scrolling than usual, with difficult levels calling for methodical strategies. 1990's "Raiden" was the beginning of another acclaimed and enduring series to emerge from this period.