Dead Defense is now available for all current iOS devices. It is a typical Tower Defense game where you must use a variety of towers and special abilities to defeat waves of various monsters and bosses. The controls are very simple, but the game play can be kind of difficult. The game does not allot you enough time between waves to set up your towers, and too many different types of monsters come at you from a variety of different directions. It also takes a few seconds for each tower to be built or upgraded, making it hard to adjust on the fly and learn the layout of each level. The restart button will be your best friend in this game.
Make sure to pay close attention to the tutorial and learn about each individual tower's abilities before you start the game. There is no encyclopedia or in-game information to help you along the way. Tapping a tower's icon during the game does not bring up its individual stats, and tapping a power up icon will only bring you to an in-app purchase screen if you do not have enough crystals to use it. Not having enough time to plan your defense, and not having easy access to a individual tower's information can make Dead Defense seriously frustrating.
UPDATE: You can see the specs for all the towers under the "Research" section.