So last week I jumped the gun and purchased the Iphone version of A.I.R. Defense and I had fun with the title but the controls were meant for a smaller screen and were less responsive on the Ipad when you X2 the image. For only 1 dollar this tower defense game is well worth the download because of it's art style, creativity and constant upgrades and weapons to unlock.
The concept of the game revolves around radar to detect incoming alien spacecraft and land vehicles. The game has a basic tutorial showing you how to attack units and upgrade your units while defending your base. Enemies can come from any side and the enemies vary from basic units (similar to tanks) to radar blocking enemies and final bosses at wave 10 on every level. There is a trick to destroying multiple enemies at once and it lies in attacking units that have grouped together. The game does get very challenging quickly and somewhat frustrating over time. But like any tower defense game there is a learning curve. For only a buck A.I.R. Defense HD is a no-brainer for tower defense fans. Chillingo put some effort into this budget title and there are multiple hours of game-play and a survival mode to unlock after the missions.