How to Build a Video Game Generator

const GENRES = ['Roguelike', 'Metroidvania', 'Tower Defense', 'City Builder', 'Survival Horror',
  'Deck Builder', 'Auto Battler', 'Puzzle Platformer', 'ARPG', 'Visual Novel', 'Rhythm Game'];

  const MECHANICS = ['Permadeath', 'Time Loop', 'Base Building', 'Crafting', 'Physics-based',
  'Procedural Generation', 'Combo System', 'Resource Management', 'Stealth', 'Diplomacy',
  'Day/Night Cycle', 'Faction Reputation', 'Card Drafting', 'Real-time with Pause'];

  const SETTINGS = ['Post-apocalyptic Earth', 'Underwater Colony', 'Victorian London', 'Deep Space',
  'Feudal Japan', 'Inside a Computer', 'Mythological Greece', 'Dying Star System',
  'Microscopic World', '1920s Noir City', 'Floating Sky Islands', 'Underground Cavern Network'];

  const ART_STYLES = ['Pixel Art', 'Hand-drawn 2D', 'Low Poly 3D', 'Cel-shaded', 'Voxel',
  'Watercolor', 'Neon Wireframe', 'Paper Cutout', 'Isometric', 'Photorealistic'];

  const PLATFORMS = ['PC (Steam)', 'Mobile (iOS/Android)', 'Nintendo Switch', 'Cross-platform',
  'Browser (WebGL)', 'VR (Quest/PCVR)'];

  const TWISTS = [
  'The world permanently changes based on player deaths',
  'NPCs remember everything across playthroughs',
  'The game gets harder the better you perform',
  'Two players control different halves of the same character',
  'The map is player-generated and shared online',
  'Every item has a hidden second use discovered by experimentation'
  ];

  function generateGameConcept(preferences = {}) {
  const pick = (arr) => arr[Math.floor(Math.random() * arr.length)];

  const concept = {
    genre: preferences.genre || pick(GENRES),
    coreMechanic: pick(MECHANICS),
    secondaryMechanic: pick(MECHANICS),
    setting: pick(SETTINGS),
    artStyle: pick(ART_STYLES),
    platform: preferences.platform || pick(PLATFORMS),
    uniqueTwist: pick(TWISTS)
  };

  // Avoid duplicate mechanics
  while (concept.secondaryMechanic === concept.coreMechanic) {
    concept.secondaryMechanic = pick(MECHANICS);
  }

  concept.elevator = `A ${concept.artStyle.toLowerCase()} ${concept.genre.toLowerCase()} set in ${concept.setting.toLowerCase()} `
    + `where the core loop revolves around ${concept.coreMechanic.toLowerCase()} `
    + `combined with ${concept.secondaryMechanic.toLowerCase()}. ${concept.uniqueTwist}.`;

  return concept;
  }