- There are three difficulty ratings for Bloons Tower Defense 2: Easy, Medium and Hard. The major difference between all three difficulties is the amount of money you start with, the number of lives you start with and the prices of different items. As the difficulty becomes harder, the money you begin with drops, while item prices inflate.
Money is important in Bloons Tower Defense 2 because without it, you can't do anything. To stop the Bloons in their path, you need to purchase different towers, such as Dart Monkeys, Tack Shooters or Cannons, which will damage Bloons as they pass by. Towers can be upgraded when a player earns enough money; the most common upgrades are attack range increases and attack power increases.
Each level that you play will bring more and more difficult Bloons. The color order of Bloons, from least powerful to most powerful, is red, blue, green, yellow, black, white, rainbow and lead. Red Bloons pop from a single dart from a Dart Monkey. Yellow Bloons are incredibly fast and must be hit four times before they finally pop. The first time you see a Rainbow Bloon, it will be the only Bloon in that level. Every time you hit a more powerful Bloon, it changes to the color below it until it pops. Hitting a yellow Bloon will change it to green, then to blue and then finally to red, when it can be popped.
- As a player, you have a number of different dart towers you can choose from. The dart-throwing towers, which aim at targets and reload faster, are the Dart Monkey, Tack Shooter, Boomerang and Super Monkey. When you click an icon under "Buy Stuff," you will have picked up a translucent image of that tower, which you can put down on your map if you have the money. The halo around the tower shows that tower's range.
Dart Monkeys cost 250, and they have a fast reload time. Without upgrades, each Dart Monkey throws a dart that can kill one red Bloon. The Long-Range Darts upgrade costs 80 and increases the Dart Monkey's range. The Piercing Darts upgrade costs 180 and allows each dart thrown by the Dart Monkey to pop two red Bloons. Again, if the Dart Monkey hits a more powerful Bloon with a dart, that Bloon will decrease one level at a time until it finally pops.
The Tack Shooter costs 340 and has a medium reload time. The Tack Shooter can shoot darts in all directions, hitting as many as eight Bloons at once. Faster Shooting costs 180 and upgrades reload time. Extra-Range Tacks costs 90 and increases the Tack Shooter's range. The Boomerang, which costs 475, is a monkey that can throw boomerangs at its targets with a medium reload time. Without upgrades, each boomerang throw can pop two Bloons. Multi-Target costs 270 and allows the Boomerang to hit up to five Bloons per throw. Sonic Boom costs 135 and allows the Boomerang to pop frozen Bloons.
Super Monkeys are the game's most powerful tower, and at 3,600, Bloons Tower Defense 2's most expensive item. If you are lucky enough to be able to purchase one during the game, you can upgrade to Epic Range for attack range and Laser Vision for attack power.
- Aside from popping Bloons, you can impede their progress with a few well-placed items. Road Spikes cost 25 and can pop Bloons that travel into them. Road Spikes can be hit a total of 10 times. Again, a higher color that contacts the Road Spikes will turn into a lesser color before popping while red. For instance, a yellow Bloon must turn to green, then to blue, and then to red, taking four hits of the 10 total for Road Spikes. Monkey Glue costs 35 per application and slows down the progress of up to 20 Bloons, giving your towers more time to pop them. Monkey Glue should especially be used to slow down yellow Bloons, which are the fastest traveling Bloon. Every item you can buy can be purchased during a round, but you will use that option most with both the Road Spikes, which you can drop in front of Bloons that have almost escaped, and Monkey Glue.
- The Ice Ball costs 385 and can freeze adjacent Bloons for a short period of time. The Wide Freeze Radius upgrade costs 180 and increases the attack range. The Long Freeze Time upgrade costs 270 and increases the amount of time Bloons remain frozen for. While frozen, Bloons can only be popped by a Boomerang with a Sonic Boom upgrade, or by a Cannon.
Cannons cost 520 and shoot bombs that can damage an entire area of Bloons. The Bigger Bombs upgrade costs 380 and increases the attack range of the Cannon's bombs. The Extra Range Bombs upgrade costs 180 and increases the range that the Cannon can shoot. Cannons will be necessary, since they are the only tower that can penetrate the lead Bloons. Put the Cannon near the front of the map, since the lead Bloon will unleash a number of black and white Bloons, which can be disastrous if the black and white Bloons are not popped early enough to unleash the high-speed yellow Bloons.
- A good beginner's strategy is to start on Easy and concentrate on buying Dart Monkeys with the Piercing Dart upgrades for the first few rounds. Set them in corners, near choke points or in another area where they have a long time to attack Bloons within their range. If you can stand it, you don't always need to use Road Spikes to destroy every Bloon that passes by, since each Road Spike costs 25 and can earn you a maximum of 10. As the levels move along, buy more Dart Monkeys with the Piercing Dart upgrades. By level 20, you should have more than enough money to invest in a Cannon. Do this, and try to get the Bigger Bombs upgrade. Again, place the Cannon near to the front of the path, since the earlier you can take out a lead Bloon, the better. Use Monkey Glue primarily for yellow Bloons to slow them down enough so that your Dart Monkeys can take care of them.