Tap Defense, the first definitive answer to the other paid TD apps, has recently hit the top 3 free apps. Tap Defense pits you against the beings of the underworld with only your trusty towers to defend the gates of heaven. In addition to money, which when unspent accrues interest at the end of every round, you also gain Halos at the end of specific rounds. They can be used to upgrade your interest rate on money or to buy new types of towers. It also offers 3 different maps to try, ranging from easy to hard.
If you’re looking for a full TD game without having to reach into your wallet make sure to give Tap Defense a try.
Update 12/11/08
Tap Defense was recently updated to ver. 1.1. This update fixed the bug used to get unlimited money (so stop e-mailing me about it. . . please) along with a couple of other balances. The only one I’ve noticed is that ice and water towers slow enemies down less than they used to (maxed ice towers now only slow by 70% opposed to 90%). If anyone else has any more info feel free to post it in your comment or e-mail me for it to be included here.
I’ve noticed the broken quake towers as well and have informed TapJoy of this problem on their Facebook page for Tap Defense. Hopefully an update will fix this soon.
Update 12/12/08
The quake tower has already been fixed in the 1.1.1 update.