As the name and description implies, the player starts with only one life and all the bloons (except for MOAB-class Bloons and their children) are Camo Bloons. Additionally, in the online version, rounds normally consisting of Camo Bloons will have Camo Regrowth Bloons instead.
Ninja Monkeys upgraded at least 1/0 are very helpful, as they can see Camo Bloons and throw projectiles quickly.
Right after the update, there was a glitch after playing this and starting a regular game, all the bloons were Camo Bloons. This would increase total difficulty of the game. However this was fixed in an update.