ElementTD app for iPhone and iPad

Element Tower Defense!!!
In Element Tower Defense ,the main purpose is to keep your lives above zero by building the defense efficently. There are 7 kinds of defense towers, 4 of which cant be build until you get relevant elements.
Choose where and which to build to block air and land enemies.
Select a sort of tower at the bottom of the screen and drag its icon onto the grassplot to attack enemies.Destroy one enemies,you will be rewarded some golds.

Every 8 levels, one diamond will be given to buy elements or to bring on the rise in interest rates.
Besides 30 glods you own 40 lives at the beginning.
The escape of one enemy will cause one life and some glods loss.
You may buy an extra life per 20 golds.
When your lives turn zero, game over.
features:
.3 difficulties for player, each has 60 levels
.Build defense during game pause
.Interest System. Once you pass a level, the golds you own will increase by the fixed interest;Using one diamond also can bring the rise in interest rates.