SoCool21's Strategy
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.
Lord N-W's Strategy
Easy: 2-1 Monkey Apprentices are a good way to start. Some levels below, add 2-2 Spike Factories and Monkey Engineers. In the last levels, try to add 1 (or 2) Bloonchipper (4-x) for deal with the MOABs.
Medium: In the first levels, buy 2 Boomerang Throwers (2-3) one for each path. Later, put 1 Spike Factory (2-2) in each path end, and some Bloonchippers for support. After level 50, upgrade Spike Factories to Spiked Ball Factories and Bionic Boomers to Turbo Charge. And in the 5 final levels, add 2-1 Dartling Guns for win.
Mael the Blade's Strategy
On easy, at least, spamming 2,3 Engineers is incredibly effective under the effect of their 3rd tier Specialty Building. On the camo rounds, use 1, 8, 7, 27, and about 25-40 Road Spikes to deal with the camos. In order of appearance from Round 24 to Round 47. Make sure you place them in the center, as it will help with dealing with them. On Medium, use the same strategy UNTIL YOU FEEL SAFE, and then work on getting a Sun God and place him on the southern cloud at the very tip (you might need to get some Sentry Guns out of the way first). However, I'd advise you get actual camo detection instead of relying on Road Spikes in this case, such as a 0,2 Monkey Village or a Meerkat Spy(ies).