I tell you how to shred a ZOMG with aussie monkeys with some help from a camo support tower.
Guide to Beat Hard Mode
Up to the First MOAB (1 – 40)
Usually I begin with 2 Boomerang Monkeys and get them both to 2-0-2 or Glaives and Red Hot Rangs which will hold back early game bloons relatively easily until round 24 when camo bloons are introduced.
Subsequently I place down my camo support tower of choice, in my case the tower is Etienne or, if you do not own Etienne, a village will also work but cost you slightly more, each camo support tower mentioned above have their own setbacks, (Etienne has to reach level 8 before the UAV provides camo detection and the village has a limited range but you can get camo detection instantly although for a price)
Once I have my camo detection tower set, I generally drop 2 more boomerang monkeys and upgrade one of them to 3-0-2 or Glaive Ricochet plus Red Hot Rangs and upgrade the other boomerang monkey to 0-2-4 or Faster Rangs plus Moab Press.
That will easily let you beat the MOAB when it arrives.
To to the First BFB (40 – 60)
After I destroy the MOAB with all the things above, I place another two Boomerang Monkeys and upgrade one of them to be another 0-2-4 or Faster Rangs plus Moab Press and upgrade the other Boomerang Monkey to 4-0-2 or MOAR Glaives plus Red Hot Rangs.
And then I work on upgrading the previous 3-0-2 (Glaive Ricochet) monkeys to 4-0-2 (MOAR Glaives).
Following all that, I place four more Boomerang Monkeys and upgrade all of them to 0-3-2 or Bionic Boomer plus Red Hot Rangs and another two Boomerang Monkeys I place down get upgraded to another two 0-2-4 to keep that BFB slow.
All of that will maul the BFB rather quickly.
To the Last ZOMG (60 – 80)
This part is pretty easy, I place two Boomerang Monkeys and upgrade them both to 0-2-4 or Faster Rangs plus Moab Press just to aid in slowing down the ZOMG and doing a fair bit of damage.
Next I place another two Boomerang Monkeys and get them both to 0-3-2 or Bionic Boomer plus Red Hot Rangs to provide that bit more damage.
Almost finally I add 2-3 more Boomerang monkeys and upgrade them to 0-2-4 to slow the ZOMG down more.
Then Finally I upgrade my 0-3-2 Monkeys all to 0-4-2 or Turbo Charge.
When the ZOMG comes, just spam all of your Turbo Charge abilities and them aussie monkeys will Shred that ZOMG.