Monkey Writing System

The  is a writing system used by the monkeys that first appeared in Bloons TD 6 and its teasers. It is an obscure language whose syntax features foreign letters substituted from Latin alphabet letters ("English letters").

Usage
The writing system first appears in a teaser from Ninja Kiwi, on 19th of April, 2018. It's a teaser hinting the upcoming Druid, and the writing system is used to spell out certain hints.

On 20th July, 2018, another teaser was posted by Ninja Kiwi, hinting the upcoming hero, Captain Churchill. The writing system is once again being used. On the same day, the writing system was decoded by u/2001serpent in this post on Reddit.

On 12th December, 2019, a new hero was teased on the game's Twitter account. The writing circling the temple's peak was revealed to be "Adora", which would later be used for the hero's name.

On 13th December, 2019, Adora's Temple was added to the game. The glyph on the temple spells "MAX SDN" horizontally and "APEX DARK" vertically. This is the first time the letter "X" appears in this writing system.

On 26th May, 2020, an image was posted on the Twitter account of Ninja Kiwi. Shown on a postcard in the image, a code that reads "Admiral" can be found, referencing Admiral Brickell which was added in the update released on the following day.

On 27th May, 2020, Bazaar was added to the game. The same writing system was used on the signs of two shops, decoded to be "KL Tea Co" and "Closed" respectively. This is also the first time the letter "C" appears in this writing system.

On 11th March, 2021, the Benjamin Matrix Placement was added to the trophy store. Benjamin also has a new Sushi Bento skin. On the skin, the sign spells out "sushi" in the writing system. This is the first time the letter "H" appears in this writing system. The letters on the matrix of the placement seems to be repeating "ABCDEF", "KLMNOP", and "UVWXY" with an unknown letter made with 2 dots after "X". This is the first time the letter "V" appears in this writing system.

On 8th/9th July, 2021, the first tower based on the merging of 3 tier 5 Dart Monkeys was unveiled on the game's Twitter account. The glyphs behind the tower artwork translate exactly to "Paragon".

On 26th November, 2021, a teaser for Bloons TD Battles 2 was posted to the game's Twitter account. It showed Striker Jones riding on a bomb/possible blimp skin. On the bomb itself, it had a code that reads: "Bloons Away!".

On 8th December, 2021, the Dart Time Stop Power skin was added to the trophy store. On the background, the code seems to be repeating "EFGCD", "ABCDE", "KLMNOP" (with "P" being written as "N"), "WXUV" etc., with an unknown character made with 2 dots after "X" again.

On 15th February, 2022, a GIF of Quincy shooting an arrow towards a heart was posted on the Twitter account of Ninja Kiwi. At the bottom left, a heart with a code that reads "To my valentine" can be seen.

Structure
It is fundamentally mostly the same as English structurally, but written in a different way than the English alphabets.

However, the "Th" digraph (a. k. a. Þ in old English) does not have the letter "H" in this writing system, but it is not left out in the case of "Sh".

Because of their similarity in looks, "D" and "U", "N" and "P" in this writing system can often found being mixed in usage, which is likely a misspell. However, if it's proved that one of them came before the other is created, it might mean it's a similar case of "假借" ("false loan words") in Chinese.