There is way to get Laser EVERY TIME before Boss at 24-alpha. After 3rd boss there is "sub-stage" with "dogs" and meteors only. This sub-stage will alternate now after every boss. All u need at these levels is to kill every "dog" exept one, then just dodge, evade and wait... wait for laser. It will apear anyway, doesn't matter when, but it will. When u see it - kill the last "dog" and pick up the Laser, then u should kill the boss as fast as it possible.
Hope i explained this well. Other way sorry for my english, remark me if it needed.