Great Ball of Fire

---

Build 100 Meteor towers.

---

From the Tower Encyclopedia: The Meteor tower targets aliens at very long range. It fires a superheated fireball that inflicts heavy area damage on impact. The meteor tower can't target units close to it, but it has the longest range of any tower make it an ideal second row tower. It is less effective against fast aliens.

This achievement requires that you build 100 Meteor towers across all of your games. Your particular playing style may mean that this unlocks naturally without any particular effort. However, if you don't tend to use Meteor towers, or simply want it to unlock more promptly, you can play Chapter 19 in Practice mode on easy and play only Meteor towers. You can easily place 100 towers on this map and unlock the achievement at the end of the game, win or lose.