Spiked Balls is the 3rd upgrade of Path 1 for the Spike Factory in Bloons TD 6. Like Spiked Ball Factory, its corresponding upgrade in BTD5, the Spiked Balls upgrade replaces standard spike piles with spiked balls. Each spiked ball pops up to 12 bloons, each spike additionally dealing 2 damage to all bloons, as well as +3 damage to Ceramics and +1 damage to all Fortified Bloons, including MOAB-class with the Fortified property.
This upgrade costs $1,955 on Easy, $2,300 on Medium, $2,485 on Hard, and $2,760 on Impoppable.