to use the Motorola 68000 processor. 3D computer graphics began appearing in several arcade games towards the end of the golden age. Funai's Interstellar, a laserdisc game introduced at Tokyo's Amusement Machine Show (AM Show) in September 1983, demonstrated pre-rendered 3D computer graphics. Simutrek's Cube Quest, another laserdisc game introduced at the same Tokyo AM Show in September 1983, combined laserdisc animation with 3D real-time computer graphics. Star Rider, introduced by Williams Electronics at the Amusement & Music Operators Association (AMOA) in October 1983, also demonstrated pre-rendered 3D graphics. Atari's I, Robot, developed and released in 1984, was the first arcade game to be rendered entirely with real-time 3D computer graphics. Gameplay Space Invaders (1978) established the "multiple life, progressively difficult level paradigm" used by many classic arcade games. Designed by Tomohiro Nishikado at Taito, he drew inspiration from Atari's block-breaker game Breakout (1976) and several science fiction works. Nishikado added several interactive elements to Space Invaders that he found lacking in earlier video games, such as the ability for enemies to react to the player's movement and fire back, with a game over triggered by enemies killing the player (either by getting hit or enemies reaching the bottom of the screen) rather than a timer running out. In contrast to earlier arcade games which often had a timer, Space Invaders introduced the "concept of going round after round." It also gave the player multiple lives before the game ends, and saved the high score. It also had a basic story with animated characters along with a "crescendo of action and climax" which laid the groundwork for later video games, according to Eugene Jarvis. With the enormous success of Space Invaders, dozens of developers jumped into the development and manufacturing of arcade video games. Some simply copied the "invading alien hordes" idea of Space Invaders and turned out successful imitators like Namco's Galaxian and Galaga, which extended the fixed shooter genre with new gameplay mechanics, more complex enemy patterns, and richer graphics. Galaxian introduced a "risk-reward" concept, while Galaga was one of the first games with a bonus stage. Sega's 1980 release Space Tactics was an early first-person space combat game with multi-directional scrolling as the player moved the cross-hairs on the screen. Others tried new concepts and defined new genres. Rapidly evolving hardware allowed new kinds of games which allowed for different styles of gameplay. The term "action games"