Castle Prototype

Castle Prototype is the first Floating Castle, it appears every time from round 1,000+. The castle isn't a boss, it is a normal floating castle. When it gets popped, 5 Floating Fortresses with 20 B.A.D. (note there will be 4 B.A.D. attached to all 5 Fortresses.).

Towers:
Each tower has 50,000 Health, they have catapults to throw stones on other towers.

Base:
The base has 40,000 Health. Inside of it, there are 5 treasure chests, 5 Diamonds, 5 Omeganium, 5 Painites and 5 Diamond Swords

Core:
The core is much stronger than a Fortress Prototype core, with 10,000 health. When the core is destroyed, you will get 1,000,000 Cash, 1,000,000 EXP, A free random tier 5 tower, 100 free Dart Monkeys, and you unlock the option to choose 3 heroes.

Attacks
The Castle will attack with the following attacks:

Launching a large rock from a catapult that will insta kill a tower with level 3 upgrade

Opening gates to send a wave of 100 D.D.T.

Mutliple Bloons with the Gun Property will stand on the towers and will start to attack them.

When the castle is at 125,000 HP, it will open its gates to send a rush of 999 Red Bloons with 0 spacing.

Finally when the castle reach 50,000 Health, it will open all of the gates of an attack of 500,000 Micro Bloons + 500,000 Clear Bloons with a spacing of 0.