Alternate Bloons Rounds (often abbreviated as ABR) is a game mode in Bloons TD 6. In standard play, it is played on Hard difficulty. This mode redesigns the first 140 rounds to be much more difficult, generally by introducing strong Bloon types earlier and having more rounds with Bloon Mods such as Camo Bloons. After round 140, the game changes to freeplay round generation with no alterations. Since the mode is normally played on Hard difficulty, rounds 1 and 2 are skipped by default and the player wins after completing round 80; rounds 81-140 are optional and rounds 1 and 2 can only be seen in other modes such as the Challenge Editor.
Rounds 101-140 do not exist in the console version due to it being based on an older version.
