Einfach das als neues Script über Main einfügen:
Code: 
class Window_Command_Horizontal < Window_Selectable
  def initialize(commands)
    @commands = commands
    super(0, 0, compute_menu_width(), 64)
    self.contents = Bitmap.new(width-32, height-32)
    @item_max = @commands.size
    @column_max = @commands.size
    @index = 0
    refresh
  end
 
  def refresh
    contents.clear
    contents.font.color = normal_color()
    @commands.each_index do |index|
      draw_item(index)
    end
  end
 
  def draw_item(index)
    contents.draw_text(text_rect(index), @commands[index].to_s, 1)
  end
 
  def disable_item(index)
    contents.fill_rect(text_rect(index), Color.new(0, 0, 0, 0))
    contents.font.color = disabled_color()
    draw_item(index)
  end
 
  def text_rect(index)
    w = width/@commands.size
    Rect.new(index * w, 0, w-32, 32)
  end
 
  def compute_menu_width
    bitmap = Bitmap.new(1, 1)
    widths = @commands.map do |command|
      bitmap.text_size(command.to_s).width
    end
    (widths.max + 32) * @commands.size + 32
  end
 
end
und dann in Scene_Title die Stelle wo eine Instanz von Window_Command erzeugt wird, durch Window_Command_Horizontal ersetzen.