i literally beat the boss on my first time encountering it. you just flip all the switches and activate that thing below it.
the third stage where it has four lasers, the areas directly above it and below it will not be touched by the lasers, so just get directly above it or below it when it starts again. so easy
and those major health guys just keep running from them while shooting with a gun, and start doing loops around that area where you found the first one.