There Can Be Only One/Strategies

Alfex's Strategy.
Buy a dart monkey and put it on the first circle. Sell it at the end of round 2 (you'll leak 6 bloons). Buy a spike factory, put it at the end of the track, upgrade it to bigger stacks. Buy a banana farm, upgrade it to more bananas. Buy a glue gunner, put it in the center of the moon, upgrade it to stickier glue, glue soak, and corrosive glue, upgrade the banana farm to banana plantation. Upgrade the spike factory to faster and even faster production, upgrade the banana farm to banana republic. Buy a monkey village, put it behind the glue gunner, upgrade the glue gunner to glue splatter, upgrade the banana farm to long life bananas and valuable bananas, upgrade the monkey village to monkey fort and radar scanner*, upgrade the glue gunner to bloon dissolver. Buy a super monkey, upgrade it to super and epic range, upgrade the monkey village to monkey beacon and jungle drums. Buy a bomb tower beside the glue gunner, upgrade it to extra range, frag bombs, and until moab mauler, upgrade the super monkey to laser and plasma blasts. Upgrade the monkey village to monkey town, upgrade the bomb tower to moab assassin, upgrade the spike factory to spiked ball factory, upgrade the banana farm to banana research facility, upgrade the super monkey to robo monkey (I used the moab assassin ability on the first bfb, but i'm not sure if I needed it), upgrade the monkey town to high energy beacon. Upgrade the robo monkey to technological terror, upgrade the spiked ball factory to spiked mines, buy a monkey ace, put it beside the tecnological terror, set it to path O, upgrade it to spy plane and spectre. After that, you can do what you want (if you buy a sniper monkey and upgrade it to cripple MOAB, the ZOMG won't get past the first circle).

.*I died around here, even with Healthy Bananas premium upgrade. This may need to be updated due to price changes. This startegy is a liar. It doesn't work. Even the "fixed" strategy.

(fixed) It's not fixed. It doesn't work.

Buy a dart monkey and put it on the first circle. Sell it at the end of round 2 (you'll leak 6-7 bloons). Buy a spike factory, put it at the end of the track, upgrade it to bigger stacks. Buy a banana farm, upgrade it to more bananas. Buy a glue gunner, put it in the center of the moon, upgrade it to stickier glue, glue soak, and corrosive glue, upgrade the banana farm to banana plantation. Upgrade the spike factory to faster and even faster production, upgrade the banana farm to banana republic. Buy a monkey village, put it behind the glue gunner, upgrade the glue gunner to glue splatter, upgrade the banana farm to long life bananas and valuable bananas, Buy a super monkey. Upgrade the monkey village to monkey fort and radar scanner, upgrade the glue gunner to bloon dissolver, upgrade supermonkey to super and epic range, upgrade the monkey village to monkey beacon and jungle drums. Buy a bomb tower beside the glue gunner, upgrade it to extra range, frag bombs, and until moab mauler, upgrade the super monkey to laser and plasma blasts. Upgrade the monkey village to monkey town, upgrade the super monkey to robo monkey upgrade the banana farm to banana research facility, upgrade the bomb tower to moab assassin, (I used the moab assassin ability on the first bfb, but i'm not sure if I needed it), upgrade the spike factory to spiked mines, upgrade the monkey town to high energy beacon. buy a monkey ace, put it beside the robo-monkey, set it to path O, upgrade it to spy plane and spectre. After that, you can do what you want (if you buy a sniper monkey and upgrade it to cripple MOAB, the ZOMG won't get past the first circle). (strategy will work adapted for positions on all maps that are intermediate or beginner, if absolutely needed spectre replaced with robo monkeys)

DVSA's Stragety
Buy a tack shooter, upgrade 3-2. Then, buy a spike factory, upgrade 3-2. Then, save enough for a 2-2 dartling gun, upgrade tack shooter to 4-2, upgrade to laser cannon, and have spiked mines by round 50. It is a good idea to have spikes r us, although you might need to add spikes at some rounds. After round 50, you can sell some stuff and possibly get a 2-3 robo monkey or sun god. By rounds 70-75, you should be all set.YAY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! YOU WIN!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

(You need tack awesomizer, sorry non-premium players)

iOS Strategy

 * 1) Buy a Tack Shooter and place it in the top-left circle, making sure the top-left spur points up the path. Upgrade to 3/0 (Tack Sprayer).
 * 2) (ASAP, should be before Round 11) Buy a Spike Factory and place it in the extreme bottom-right of the level, so the only track in its range is the final chute. Upgrade to 3/0 (Spiked Ball Factory).
 * 3) * Spike Factory earns its first pop in Round 22 usually.
 * 4) ASAP, should be before Round 32) Buy a Dartling Gun and place it below-and-right of the Tack Shooter, but within the large top-left cresent shape. Upgrade to 3/2 (Laser Cannon with Depleted Bloontonium) via 1/0, 1/2, 3/2.
 * 5) (ASAP, should be before Round 50) Upgrade Spike Factory to 4/0 (Spiked Mines). As soon as you can, upgrade further to 4/2 (Even Faster Production).
 * 6) (ASAP, should be before Round 53) Buy a Super Monkey and place it next to, bottom-right of the Dartling Gun.
 * 7) (ASAP) Buy a Dart Monkey, place it within the Tack Shooter's circle, and upgrade it to 4/0 (Juggernaut). SET PRIORITY TO LAST. This helps immensely with those tough ceramic bloons.
 * 8) Upgrade Super Monkey to 2/2 (Plasma Vision with Epic Range) via 2/0, 2/2.

Tips for later rounds (order not necessarily perfect, apologies there, but the concept is there):
 * Buy a Bomb Tower and place it in the small circle with the Tack Shooter and Dart Monkey. Upgrade to at least 2/3 (MOAB Mauler with Frags), and later to 2/4 (MOAB Assassin). Have priority set to STRONG and use the Assassin on BFBs.
 * Buy an Ice Tower and place it between the dot and the top-left arc of the bottom-right circle. Upgrade to at lease 2/3 (Ice Shards with Snap Freeze), later to 2/4 (Absolute Zero). This is mostly used to slow down MOAB-class bloons when they are dense.
 * Upgrade Tack Shooter to 4/0 (Ring of Fire).
 * Upgrade Super Monkey to 2/3 (Robo-Monkey).
 * Buy a Monkey Ace and place it dead center. Upgrade to 2/4 (Ground Zero with Sharper Darts). Perhaps "O" path is best, but basically Ground Zero acts as a "Get Out of Jail Free" card when you get overwhelmed.
 * Buy a Mortor Tower and place it... Well, wherever. Aim usually near the Tack Shooter, but obviously tweak as needed. Upgrade to 2/4 (Artillery Battery with Bigger Blasts).

This strategy requires good shooting with the Dartling Gun, so the best advice that can be offered is to turn off Fast Forward during MOAB rounds. Also, be very aware of where he is aiming, since upgrading towers and using abilities changes his heading.