I haven't completed the track yet but I have figured out a way to start that is guaranteed to work. Have the Dart Speciality upgraded fully and have 2 dart monkeys (1 free, obviously) and upgrade to 1,0. You could also chose a cheaper option if you don't have the specialitiy yet, by buying the cash injection and getting super monkeys. I am trying my hardest but I cannot complete it on easy. If you buy 3 life injections and have 2 engineers and tack shooters, you could win.