DragonRuby Game Toolkit - Bunnymark - https://youtu.be/E_f7UkznMjY

main.rb

class Rabbit
  def initialize x, y, w, h
    @x = x
    @dx = [1, -1].sample

    @y = y
    @dy = [1, -1].sample

    @w = w
    @h = h
    @path = "sprites/wabbit_alpha.png"
    @speed = rand * 10
  end

  def move
    @x += @speed * @dx
    @y += @speed * @dy
    if @x < 0
      @x = 0
      @dx = 1
    elsif @x > 1280 - @w
      @x = 1280 - @w
      @dx = -1
    end

    if @y < 0
      @y = 0
      @dy = 1
    elsif @y > 720 - @h
      @y = 720 - @h
      @dy = -1
    end
  end

  def draw_override ffi_draw
    move
    ffi_draw.draw_sprite @x, @y, @w, @h, @path
  end
end

def tick args
  args.state.rabbits ||= []

  # every click adds 10k bunnies
  if args.inputs.mouse.click
    10000.times do
      args.state.rabbits << Rabbit.new(1280 * rand, 720 * rand, 32, 32)
    end
  end

  args.outputs.debug.watch GTK.current_framerate
  args.outputs.debug.watch args.state.rabbits.length
  args.outputs.sprites << args.state.rabbits
end