       @rocks.each drawDrawable
 
       @sprite_man.pos = @man.body.position.plus(@pos)
+      @sprite_man.pos.y = 600 - @sprite_man.pos.y
       @sprite_man.rotation = -@man.body.rot.angle()
 
       @sprite_arm.pos = @arm_pos.plus(@pos)
+      @sprite_arm.pos.y = 600 - @sprite_arm.pos.y
       @sprite_arm.rotation = -@mouse_pos.minus(@man.body.position).angle()
       if @mouse_pos.x < @man.body.position.x
-        @sprite_arm.rotation += 180
+        @sprite_arm.rotation += Math.PI
 
       @sprite_tank.pos = @pos.plus(@ceiling.body.position)
+      @sprite_tank.pos.y = 600 - @sprite_tank.pos.y
 
       if @sprite_claw.visible
         @sprite_claw.pos = @claw.body.position.plus(@pos)
+        @sprite_claw.pos.y = 600 - @sprite_claw.pos.y
         @sprite_claw.rotation = -@claw.body.rot.angle()
 
     drawPrimitives: (context) =>

      # drawable things
      drawDrawable = (drawable) =>
        drawable.sprite.pos = drawable.shape.body.position.plus(@pos)
        drawable.sprite.rotation = -drawable.shape.body.rot.angle()
        true
      @atoms.each drawDrawable

    drawLine: (context, p1, p2, color) =>
      context.strokeStyle = "rgb(#{color[0]}, #{color[1]}, #{color[2]}, #{color[3]})"
      context.beginPath()
      context.moveTo(p1.x, 600 - p1.y)
      context.lineTo(p2.x, 600 - p2.y)
      context.closePath()
      context.stroke()

