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, and, in BTD5, adds an ability called Spike Storm, which takes about 1 minute to recharge.

Trivia

 * In BTD5, the Spike Storm is an ability.
 * It lasts much longer than in BTD4 to use the Spike Storm.
 * In Bloons TD 4, Spike Storm will occasionally only cover 1/4 or 1/2 of the track.
 * It shoots faster than M.O.A.B. SHREDR Spikes without Spike Storm.