//should scale your shadow depending on each coin lane.
if(y == 500 )// y is equal uppery then will scale to .6 of normal size
    {
    draw_sprite_ext(shadow,0,x,y+40,.6,.6,0,c_white,1)
    }else if (y == 500)//y is equal to middley then will scale to .8 of normal size
            {
            draw_sprite_ext(shadow,0,x,y+40,.8,.8,0,c_white,1)
            } else{ // the spritee will draw normal size on lowery lane.
                    draw_sprite_ext(shadow,0,x,y+40,1,1,0,c_white,1)
                }