Spike Storm (BTD4-BTD5)

"Every 15 seconds the factory generates a storm of short-lived spikes, filling up the whole track."

- BTD4 description

"Lays down a thick carpet of spikes over the whole track."

- BTD5 description

Spike Storm is the final upgrade for the Spike Factory in Bloons TD 4, and the final upgrade of Path 2 in Bloons TD 5. This upgrade allows the Spike Factory to cover the track with an almost unstoppable wave of short-lived spikes (they disappear quickly once the effect is over) every 15 seconds in BTD4. In BTD5, it appears as an activated ability and has a 60 second cooldown. In addition, it does heavier damage to MOAB-Class Bloons because it has the MOAB-SHREDR Spikes upgrade before it.

In BTD6, this upgrade returns with similar features to the BTD5 ability. See Spike Storm (BTD6) for more detailed info.

BTD4
Easy: $5950, Medium: $7000, Hard: $7560

BTD5
Easy: 5525, Medium: $6500, Hard: $7020, Impoppable: $7800

Tips

 * This can be used to handle MOAB-class bloons across the screen.

Trivia

 * In BTD5, the Spike Storm is an ability that takes much longer than in BTD4 to coat the track in spikes. That's because in BTD4, it didn't have the MOAB SHREDR Spikes upgrade.
 * In Bloons TD 4, Spike Storm will occasionally only cover 1/4 or 1/2 of the track. This is most likely a bug.
 * The ability throws out a total of 250 piles of spike.
 * The Bigger Stacks upgrade (1/x) affects spike piles from the ability as well as the actual Spike Factory, meaning that players can cover the track with the larger spike piles with 10 spikes each rather than the tiny ones with only 5 each.
 * With said upgrade, each spike pile is does 40 damage (as much as 4 MOAB Maulers for one pile). This is useful against a ZOMG since its larger hitbox means more of these spikes will hit it.
 * The Spike Storm ability in BTD5 is very effective against a rush of MOABs.
 * The Spike Storm ability can almost wipe out a whole B.F.B.
 * The Spike Storm can pop the outer layer of 9 D.D.T.s (with White Hot Spikes or MIB support).
 * In BTD Battles, spamming 1/4 Spike Factories is an extremely useful way to survive in late rounds, as Super Monkeys are not as useful as they are in BMC and BTD5. They are also useful in later levels of Boss Bloons because they deal heavy damage to the boss bloon and the naturals.