The Spike Factory creates piles of spikes within its range. At first each pile contains 3 spikes but it can be upgraded to have more spikes per pile. Costs $750.
Spike pile now pops 12 bloons
Total cost: $1,450
||Unlock the challenge for this tower by unlocking 5M (Nebula).
Complete the challenge to unlock 3S (Shield Generator).
Produces spikes nearly twice as fast
Total cost: $2,700
Spike Ball Factory
Does more damage to armored bloons
Total cost: $5,100
Titanium spikes pop twice as much and last longer
Total cost: $5,700
Does more damage to MOAB class bloons
Total cost: $6,100
Shields that block and pop bloons
Total cost: $6,200
Mines explode when they run out of spikes
Total cost: $13,600
Big spike pile pops 75 bloons
Total cost: $13,500
Generates more spikes that home in on MOABs
Total cost: $14,000
Much stronger forcefields
Total cost: $17,700
Spike wall blocks thousands of bloons
Total cost: $23,600
Creates mini-stars that pop 300 bloons
Total cost: $38,500
Covers the track in spikes
Total cost: $27,000
Place the entire track on lockdown
Total cost: $59,700
Total to fully unlock: 88
- Can pop camo by default.
- Can pop lead with all upgrades tier 3 and beyond.
- Can damage HTAs with all upgrades tier 1 and beyond.
- The homing spikes from 4R have infinite range.
- 5M factory deals damage to shielded or static bloons instead of popping them on contact.
- Nebulas regrow over time, as long as they haven't reached their lifespans.
- Stack path upgrades cannot bounce back DDTs, ZOMGs and Trojan Bloons, but can slow down DDTs.
- Can deal with bloons that sneak by your defenses.
- Has powerful abilities.
- Left path is good at taking out MOAB class bloons.
- Stack path gives towers more time to target bloons.
- A single nebula factory can solo a ZOMG.
- Bad against shielded bloons and static bloons.
- VERY expensive at higher tiers.
- Ineffective if placed near the path entrance.