Bloons Tower Defense

Bloons Tower Defense (also known as Bloons TD) is a series of tower defense games under the "Bloons" series created and produced by Ninja Kiwi. The game was initially developed as a browser game, built upon the Adobe Flash platform and released in mid 2007. Later games in the series expanded to support various mobile platforms, including Android, iOS, Windows Phone, PlayStation Portable, and Nintendo DSi.
In the game, players attempt to prevent balloons (referred to as "bloons" in-game) from reaching the end of a set course by placing towers or road items along it that can pop the bloons in a variety of ways, typically by utilizing the power of monkeys. Some towers can stall the bloons and give the other towers more time to pop them by freezing and gluing the bloons. Money is gained by popping bloons, completing levels, and collecting bananas from existing banana farms which can be spent on new towers, upgrades for existing ones, or temporary items such as exploding pineapples and road spikes.
Gameplay.
The main objective of "Bloons TD" is to prevent balloons, known in-game as "Bloons", from reaching the end of a defined track on a map which consists of one or more entrances and exits for the bloons. The game is a tower defense game and thus the player can choose various types of towers and traps to place around the track in order to defend against the bloons, gaining 1 in-game dollar for every layer of bloon popped. If a bloon reaches the end of a path, the player loses lives (or in later games, health); once these are all depleted, the game ends. The bloons always follow the map's set path on the track until they either reach the exit(s), are popped, or are moved to an earlier part of the track by a tower's ability.
There are two classes of bloons in the game: regular (unnamed in the game) and MOAB-class. As of "Bloons TD 6", the regular bloons consist of: red, blue, green, yellow, pink, black, white, lead, zebra, rainbow, purple, and ceramic bloons. MOAB-class bloons are in the shape of a blimp and consist of: the MOAB (Massive Ornary Air Blimp), the BFB (Brutal Flying Behemoth), the DDT (Dark Dirigible Titan), the ZOMG (Zeppelin Of Mighty Gargantuaness), and the BAD (Big Airship of Doom). Tougher variants of most bloon types contain a number of specified weaker ones. In later versions of the game, regular bloons possess sometimes special characteristics such as camo (which most towers cannot detect), regrowth (the ability for the bloons to slowly grow back to their original size), and fortified (which doubles the health of the toughest bloons), that resist certain tower types. With each level, the intensity of bloon waves proportionately increases.
Towers are the main defensive utility in the "Bloons TD" series. Each tower has its own unique purpose, power, and use, with some being powerful against specific bloons but unable to target others effectively. Every tower can be upgraded to increase power and other capabilities by spending the in-game currency, known simply as 'money', which is earned by popping bloons and at the end of each round. In "Bloons TD 4" onwards, certain towers such as banana farms can be placed to produce additional money during a round (end of the round in "Bloons TD 4").
In later games, there are multiple difficulty levels; for instance, in "BTD5", there are four difficulty levels and in "Bloons Monkey City" there are five. The higher the difficulty the player plays on, the fewer lives they have and the more each tower and upgrade cost. There are also different types of maps rated by difficulty; in general, there are more types of maps in newer games.
Main entries.
There are currently six released numbered games in the "Bloons TD" series apart from various add-on packs and spin-offs such as "Bloons TD 4 Expansion" and "Bloons Monkey City". The newest release, "Bloons TD 6", was released on June 14, 2018. The series was retitled from "Bloons Tower Defense" to "Bloons TD" in 2009 due to infringement on the "Tower Defense: Lost Earth" trademark owned by Com2uS.
"Bloons Tower Defense" and "Bloons Tower Defense 2".
"Bloons Tower Defense" is the first game in the "BTD" series, released in mid 2007 as a free flash browser game. In the game players had to defend against colored bloons with monkeys, dart throwers, and other towers positioned around the map. Bloons have varying numbers of layers, with each layer being pierced revealing the layer underneath until the bloon has been completely popped. If all lives are lost, the game is over. If all waves are passed, the player will win the game.
"Bloons Tower Defense 2" was released soon after in late 2007, adding new towers, multiple map options, new bloons, and an option for the game's difficulty.
"Bloons TD 3".
"Bloons TD 3" was released on September 5, 2008, months after the release of "Bloons Tower Defense 2", named differently due to a trademark dispute with Com2uS. As with the second game, new towers, bloons, and maps were added.
A version based on this game was released for iOS titled "Bloons TD"; made available on October 3, 2009 from the iOS App Store. This version had extra maps styled in snow and beach themes, and included OpenFeint achievements.
The game included five map packs, containing a total of 15 different levels to play, with packs unlocked by completing the previous levels. This version of the game was also released for the PlayStation Portable in 2010.
Another version of the game, simply titled "Bloons TD", was released for DSiWare in 2011, containing 50 rounds to complete.
"Bloons TD 4".
"Bloons TD 4" was released on October 26, 2009 as an online freemium game with a proprietary iOS version released on December 7, 2010, developed in conjunction with Digital Goldfish. A "sandbox mode" allows experimentation with weapons and enemies, and an "apocalypse mode" makes the gameplay continuous without pausing between levels.
The gameplay underwent changes including a graphical update, the ability to save the current game, and the introduction of an unlock-based leveling system. The tower upgrading system received various changes including increasing the number of upgrades per tower, and new maps and game modes were added.
iPhone and iPad versions of this title have been purchased over one million times. A version of the game was also released as a DSiWare game in 2012.
"Bloons TD 5".
The original (Flash and freemium) "Bloons TD 5" was released on December 13, 2011. The proprietary version of "BTD5" was released on iOS worldwide on November 15, 2012 for iPhones and iPods with improved graphics and additional upgrades, tracks, towers, and bloon types. On November 19, 2014, it was released on Steam.
"Bloons TD 5 Deluxe" was released on January 27, 2012, which sets a certain goal the player may achieve to be rewarded with more in-game currency. Also with a new update for the mobile version of "BTD5", a new tower was added called the "Monkey Sub". The submarine was later added to the online version on July 20, 2015.
This game also has an unlimited round free play mode, which can have bloons with increasing strengths until the Z.O.M.G type M.O.A.B class bloon. Speed and health ramping also buff the blimp hp throughout the rounds. The Steam/Mobile version has two special mode bosses, the Dreadbloon and Blastapopoulos. The iOS, Android, and Steam versions have 15 languages: English, Arabic, Danish, Finnish, French, German, Italian, Japanese, Korean, Norwegian, Portuguese, Russian, Spanish, Swedish, and Turkish. On March 3, 2017 it was released for Microsoft's Xbox One, later releasing for PlayStation 4 on May 9, 2017 and Nintendo Switch on June 13th, 2018, all of which cost $14.99 USD.
"Bloons TD 6".
"Bloons TD 6" is the newest game in the main "Bloons TD" series. After being announced on March 28, 2017, it was released for the iOS App Store and the Google Play Store on June 14, 2018. A Steam version was released on December 17, 2018. Unlike all earlier games, "Bloons TD 6" does not have a Flash-based counterpart on the Ninja Kiwi website.
Along with 3D graphics, new features added include three new bloon types, each with unique properties such as immunity to magic and fire, extra health, or immunity to slowing and knockback. Some maps contain obstacles that block the sight of certain towers. Some obstacles are able to be removed by paying a sum of in-game money.
Spin-offs.
Apart from the main series, Ninja Kiwi has made several "BTD" games that include the core gameplay of "BTD" but are not numbered sequels.
"Bloons TD Battles".
"Bloons TD Battles" was released on December 12, 2012, and later to Android and iOS platforms in-between November 5 and 6, 2013, respectively. On April 20, 2016, it came to Steam as a ported version.
The gameplay is similar to that in "Bloons TD 5" but two players compete against one another in one of four game modes. In "assault" mode and battle arena, each player normally progresses through the levels that are usually equal to 2x-1 in terms of BTD5. Example, round 7 in BTD Battles would be round 13 in BTD5. However, the players are also given the ability to purchase additional bloons, sending them to the opponent, overwhelming them. 
In "defense" mode, the players play a natural game, the screen split vertically. Players can spend money to increase their income. In "Card Battles" mode, the players choose from a selection of cards to use in their games. The cards have two functions: Sending bloons to the enemy player, which, like in Assault Mode, will give the player who sends the bloons income, and placing down a tower. All three game objectives are to outlast the opponent in surviving the bloon attacks. Using the games' skill-based matching system, players can be automatically matched with one another. The last mode is Club Battles, where you can choose 1-3 powers from 6 powers, when you play with friends or it is randomly chosen every day from the 6 powers when you play with randoms, you get a club ticket every day at 7 PM or you can get a Club Ticket from the daily wheel. Another mode is Battle with friends which you can play 1 of the 4 modes with a friend,not a random player, to join your friend you need to enter a code which will connect you with your friend.
"Bloons Monkey City".
"Bloons Monkey City" was released on November 25, 2013. Like "Bloons TD Battles", the core gameplay is similar to that of "BTD5", however, the player has to maintain a city, expanding the city by capturing bloon-infested areas called tiles. One important goal of the game is levelling up the city. Players earn XP for the city by capturing tiles, completing missions or building towers. Earning higher levels with XP grants access to certain unique game features, like Monkey vs. Monkey, Monkey Knowledge, etc.
There is also an in-game feature known as Monkey vs. Monkey, allowing players to fight each other; raids can be launched using the resource "Bloontonium". This can be acquired by capturing certain tiles or with Bloontonium generators. If the opponent fails to defend against the raid in the set time period, the attacker gains city cash, another resource in the game used to build towers, bloonstones, the 'premium currency' of the game, and city honor, which has no primary purpose in the game other than achievements.
One primary difference between this game and the others in the "Bloons" series is the addition of buildings. Buildings in "Bloons Monkey City" are required in order to use and upgrade towers. Some buildings serve as prerequisites to other buildings, while others are prerequisites to using certain bloons in raids. The number of towers the player can use in a game is determined by how many of the corresponding type of building the player possesses. Some buildings unlock new monkeys, while others unlock upgrades for these monkeys. Other buildings are required to unlock the tier four upgrades, camo bloon defense, and MOAB-class bloon popping power (the Sun God and Robo Monkey also require buildings). This game contains 3,000 Tiles, and a new MOAB-class bloon, the DDT (or Dark Dirigible Titan).
In mid-2014, Ninja Kiwi released a new mode known as Contested Territory, a mini-game which offers bonus rewards, and pits players against each other, all of whom compete to survive the most rounds for the longest time on a trickier-than-normal track. This game was released on browsers, but a port to iOS and Android was released on December 3, 2014 and February 18, 2015, respectively. The Steam version was released on April 10, 2020.
"Bloons Adventure Time TD".
"Bloons Adventure Time TD" is a crossover game between Ninja Kiwi's "Bloons TD" series and Cartoon Network's "Adventure Time" series that was announced via the Cartoon Network International News Site and the Ninja Kiwi blog on March 8 and 9, 2018, respectively.
The game soft launched on July 14, 2018 in Australia, New Zealand, Philippines, and Singapore on Android and iOS and later launched internationally. The game features characters from Cartoon Network's "Adventure Time" such as Finn the Human, Jake the Dog, and Princess Bubblegum as well as new monkey heroes like Max, Cassie, and C4 Charlie.
The gameplay is similar to other games in the series, with a new weapon and item mechanic as well. There are at least 15 adventures and 50 maps to play in that act as the playing stage of the game.
Reception.
Shortly after the release of "Bloons Tower Defense", Lore Sjöberg of Wired described the game as cheerful and addictive, calling it "pop culture at its best". In 2012, Justin Davis of IGN described "Bloons Tower Defense" as one of the best free tower defense games, despite its "amateurish" artwork. He later noted the first entry's lack of depth, and that the sequel improved this.
IGN editor Daemon Hatfield said that he thought "Bloons TD 3" succeeded in standing out in the crowded genre by having sufficient core game mechanics and adding an individual twist. The game's iOS version received mixed reviews with some authors praising the unique towers and good gameplay, though the user interface, controls, and lack of leaderboards were criticized. The DS version received similar reception, with Lucas Thomas of IGN describing it as "a pretty good take on good old Bloons TD." Eurogamer's Kristan Reed gave the PSP version 8/10, describing it as "transfixing", though he said that the music appeared to be designed to "drive you insane".
GameZebo editor Jim Squires gave "Bloons TD 4" a 3.5/5 rating, praising it on its well designed maps and towers and for having a large amount of content, but he criticized the game for not "bringing anything new to the genre." "GamePro" editor Ryan Rigney gave "Bloons TD 4" a 2/5 rating, stating that it had the same "Bloons Tower Defense" gameplay as the previous titles, and "the screen eventually gets so hectic that it's no longer fun to play"; an issue which many other reviews also responded negatively to.
"Bloons TD 5" was received similarly to its previous version, with reviewers commenting positively on the number of maps, towers, and levels, but criticising the lack of innovation to the tower-defense genre and performance issues at higher levels. Both "Bloons TD 4" and "Bloons TD 5" featured among the top 10 paid iPhone apps in the iOS App Store, with "Bloons TD 4" selling over 1 million copies. "Bloons TD" remained in the top 100 apps for at least 3 months, and "Bloons TD 5" was the 8th most purchased iPhone app in 2013. Overall, the game series has been played over 1 billion times across web and mobile devices.
"Bloons TD 6" received praise for its extended gameplay variety, but has also been criticized for its lack of replayability despite the increased number of unique elements in the game.
The success of the "Bloons TD" franchise had been given praise by digital investment company Modern Times Group, with special note on Ninja Kiwi's continuous work to "pioneer" the tower defense genre in an economically viable but quality format.