run.rb

require_relative 'video_game'
require 'pp'

wow = VideoGame.new(types: ['rpg'], genre: :mmo, name: 'World of warcraft')
pp wow.types # => ['rpg']
wow.types = []
pp wow.types # => ['rpg']

puts 'game2'

game2 = VideoGame.new(types: ['rpg'], genre: :mmo, name: 'World of warcraft')
pp game2.genre

puts 'print title'
pp game2.title


wow = VideoGame.new(types: ['rpg', 'fps', 'strategy'], genre: 'mmo', name: 'World of warcraft')

puts wow
puts wow.title

video_game.rb

require 'pp'

class VideoGame

  def self.types
    { mmo: 'Massively multi player' }
  end

  def initialize(attributes)
    self.name  = attributes[:name]
    self.types = attributes[:types]
    self.genre = attributes[:genre]
  end

  attr_accessor :types, :name, :genre

  def types=(types)
    raise 'types should be an array' unless types.is_a? Array
    @types = types
  end

  def types
    @types ||=[]
    @types.shuffle
  end

  def genre=(genre)
    genre = genre.to_sym
    raise 'invalid genre' unless VideoGame.types.keys.include?(genre)
    @genre = genre
  end

  def genre_name
    VideoGame.types[genre]
  end

  def title
    "#{name} genre:#{genre_name} and types: #{types.join(', ')}"
  end

end