"Axis of..." Completion List

This is a list of all the Axis of... challenges I have attempted in CHIMPS Mode.
I have listed only those that are realistically possible, along with the overall cost of the towers combined. This list will contain what maps I have attempted the runs on as well as the difficulty of the challenge altogether post completion.

Criteria for Completion:
I have my own rules for which I abide by when it comes to completing the Axis of... challenge. For a start, all Tier 5 towers must be purchased BEFORE Round 100 is beaten. The final Tier 5 can be purchased during Round 100, but not after the BAD has been beaten. Secondly, it is not required to complete CHIMPS Mode to clear the Axis of... challenge. However, I will pursue to beat Round 100 regardless before making judgement on the Tier 5 combinations.

Sniper Monkey

Stats

• Approx. Cost: $105,000
• Tower Synergy: Strong
• Difficulty: Easy
• Map Completions: Logs

This is the original Axis of... challenge. It offers you a lot of leeway in terms of cost, and given how cheap two of the Tier 5 upgrades are, they can be purchased relatively early compared to most others. The difficult part comes in the late-game when MOAB-class Bloons spawn more often. For this, you will need to beef up your defense as Sniper Monkey's aren't the best source of MOAB or super-ceramic damage in the game. Other than that, you should be able to beat this challenge on any map.

Boomerang Monkey

Stats

• Approx. Cost: $161,250
• Tower Synergy: Decent
• Difficulty: Medium
• Map Completions: Logs

The most expensive Axis of... challenge that is feasibly possible. There's very little wiggle room in terms of what else you can afford, so it is best that you focus instead supporting the on Boomerang Monkeys' instead of complimenting them with strong towers. Aside from that, the challenge itself shouldn't prove that difficult at any point of the run, as the three Boomerang Monkey's can provide enough power to pop all Bloons at all stages, though it is important to consider which upgrades you want and when. It may be better off to buy than to save up.

Ice Monkey

Stats

• Approx. Cost: $110,000
• Tower Synergy: Strong
• Difficulty: Easy
• Map Completions: Frozen Over

My personal favourite Axis of... challenge. Each Tier 5 Ice Monkey backs up the others so effectively and provides something useful for the team at every point of the battle, especially Absolute Zero which doubles the attack speed of Super Brittle and Icicle Impale. And since you have the cash to spend on MOAB defence early on, you can afford to overspend. But once you get the Axis of Ice set-up, the rest of the game should be trivial.

Monkey Buccaneer

Stats

• Approx. Cost: $102,750
• Tower Synergy: Good
• Difficulty: Easy
• Map Completions: Winter Park

For the cheapest possible Axis of... combination, this is understandably the easiest you can do on a map with water. But there's another reason: these towers are POWERFUL together! For a start, Carrier Flagship provides extra speed to all water-based Monkey's nearby, including the heroes Pat Fusty and Admiral Brickell. The only downside is that Trade Empire isn't a very powerful tower on its own, but that's because it's not meant to be used in CHIMPS mode... even with all of the buffs.
But what makes this Axis of... even better is that you have cash in reserve to purchase a Sky Shredder, which works wonders under the influence of the Carrier Flagship buff. And if you have Admiral Brickell as your hero, then you're pretty much good to win.

Mortar Monkey

Stats

• Approx. Cost: $143,500
• Tower Synergy: Mild
• Difficulty: Hard
• Map Completions: Logs

Micro-city! That's what the majority of this Axis of... challenge boils down to. And MAN is it not fun! For the best part of this run, you'll have to manage where your mortars are aiming to make sure you can pop everything and not leak a single thing. And you don't have a lot to play around with, either, so you're basically locked into managing THREE Mortars all at once!
Fortunately, you have a massive leg-up in that you can use Striker Jones to buff your Mortar Monkeys', and he provides incredible synergy with them. At the very least, this challenge just goes to show how good Striker Jones and Mortars are in combination with each other.

Ninja Monkey

Stats

• Approx. Cost: $125,000
• Tower Synergy: Good
• Difficulty: Medium
• Map Completions: Cubism

Ninja Monkey's are arguably the best cheap tower in the game, and they also prove to be an effective force when put together. This Axis of... challenge is one that can be accomplished with relative ease, but making it an effective working unit is the hard part despite all the positives. This is largely due to how the Ninja Monkey struggles against densely packed Bloons at all levels, making late-game and regrow farms more of a hassle than they should be. If you are aiming to beat Round 100, then you absolutely NEED the back-up! You have a bit in reserves, but try not to get carried away.
Axis of Espionage - as I like to call it - using ONLY Ninja Monkeys is completely possible, but it will prove to be tediously challenging.