How do you beat the 50 year behemoth

first you have to go to the forest.once you go in there will be a stick.once you have it you have to whack these mosquito type flies.keep going and then you will find the factory.go right then click on the barrel then the window to get the hacksaw.go back to see whole front factory.go to wooden door and use the hacksaw to break the lock.your hacksaw will break too.now go into supplies room to get funny glasses.go back and go to generator room and turn left to get the gun.shoot the fire salamanders then a repticore's tentacle will come busting through the windows.use your sandwich to make it go away.then the brick wall will break then go in the room.turn left then get the wheel go back to elevator room.turn left and click on the machine.put the wheel on.go back to the room in the generator room. put on the glasses then click on the buttons.go back to elevator room and use the elevator.go to supplies room.get the light bulb to your left and put it on the holder in the dark room.go in and click on the key and get it.go back out and go down the hall.go to janators room and click on a locker on your left all the way.take the key and go out.go left and put the key in.do the code.click on third little screen and try and get the fission gun.once you get it click on the big screen and get the screwdriverclick on the air vent and screw out the screws.go on the helicopter and ride it to get to the behemoth.shoot the targets on the head until it explodes.then you have finished the mission!