|"NOW UPDATED WITH NEW THE NEW TOWERS! Use your favourite new towers, the Dartling Gun and the Spike Factory in this awesome expansion pack for BTD4. Bloons Tower Defense 4 Expansion contains 4 brand new crazy fun tracks for you to try out. Mesmerise yourself on the Sandy Spiral Track, get lost in the Subterrainian Sewers*, explore the secrets of the Monkey Temple, or challenge your wits on the Triangle of Insanity! This expansion also includes a new game mode called Deflation mode. You start Deflation mode with 50,000 money but you never get any more. Finally, we have included Tower Specialties, which you will unlock after completing the new tracks in various difficulty levels. The specialties allow you to customize your strategy by making some towers much cheaper to buy, at the expense of increasing the cost of all others. Enjoy Bloons Tower Defense 4 Expansion only on Ninja Kiwi!"|
|— Official Description|
- *At the time of publishing, this typographical error indeed existed.
Bloons Tower Defense 4 Expansion is an expansion pack built to add to the Bloons TD 4 experience. There are 4 new maps, as well as a new mode called Deflation Mode, and a new feature called Specialist.
- Main article: Specialist
This little brainwave allows you to specialise in certain tower types by making them cheaper for the duration of the game, while making the rest of the towers more expensive. For example, the “Classic” specialty allows you to specialise in Dart Monkeys, Tack Shooters, Boomerang Throwers and Road Spikes. When you do this the costs of those towers and upgrades are reduced by 20% and all other towers' and upgrades' costs are increased by 10%. This adds a really neat level of flexibility to your gameplay and allows you to pick a style to suit the track and to really stretch out into different strategies. You have to beat it on certain difficulties and on certain tracks.
- Classic: Beat the beginner track on easy or harder.
- Support: Beat the intermediate track on medium or harder.
- Munitions: Beat the advanced track on medium or harder.
- Vehicles: Beat the beginner track on hard.
- Slow Down: Beat the intermediate track on hard.
- Supernatural: Beat the expert track on medium or hard.
- New Towers (new): Beat the advanced track on hard.
- Beginner Track: Sandy Spiral
- Intermediate Track: Subterranean Sewers
- Advanced Track: Monkey Temple
- Expert Track: Triangle of Insanity
Bloons TD 4 Expansion Advanced Track SecretEdit
- Main article: Monkey Temple (Track)
In Bloons TD 4 Expansion, the advanced track is a Sun God temple containing a secret. To unlock the secret, you must have a mininum 40 towers and 30,000 money. You will then be asked if you want to unlock the secrets of the temple by sacrificing 30,000 money (easy) and 40 towers (the Towers will be taken from the older ones to the newer). After accepting, lightning strikes the eyes of the Sun God temple which glow, and you will hear thunder. It shoots sun beams three times as fast as Sun Gods. It can take on the B.F.B. solo and complete level 74 alone. Here is a link if you want to see it with sound:  It can destroy an M.O.A.B. in a second or two.
- Main article: Deflation Mode
Deflation Mode is unlocked at Rank 32. In Deflation Mode, the player starts on Round 20-21 with 50,000 money on Medium Difficulty. Popping a bloon doesn't give money, Banana Farms are disabled, and no money is given for passing a round. Note this is for the few that know what they are doing. Please note that you can only afford to have one Sun God.