Ground Zero (BTDB2)

"Increases effectiveness of bomb drops. Ground Zero Ability: drops a huge bomb that destroys most things on screen."

- BTDB2 description

Ground Zero is the 4th upgrade on Path 2 of the Monkey Ace in Bloons TD Battles 2. It is similar to its BTD6 counterpart, except its ability lacks an initial cooldown and has the old BTD6 cost.

It costs $14,000.

Summary
The main part of Ground Zero that makes it special is its nuke ability, which near-immediately nukes the screen with huge damage at an extremely high pierce. The stronger bomb arrays can deal extra damage too as a bonus, more than tripling its damage. It's particularly useful if your opponent rushes with hordes of Fortified MOABS,as the ability will erase everything on sight.

Tips

 * 1-4-0 is generally better because of the attack speed bonus, though the ability does not gain improvements with crosspaths.
 * 0-4-1 increases the pierce of the bomb arrays, which may help clear dense rushes more effectively, albeit at a slower rate.
 * Make sure to have at least two Ground Zeros up at any given time past round 26, as fortified DDTs require two abilities to destroy, and of course, be weary of the 0.8 deploy time, as to not have the DDTs clear the exit before the nuke lands.