If there's a bigger game genre for the iPhone than Tower Defense clones, I haven't found it. A quick search of the App Store reveals well over 100 titles matching that description.
No surprise there: the iPhone's touch screen lends itself perfectly to this kind of game (which, for the uninitiated, requires strategic placement of defensive armaments to ward off increasingly powerful attackers).
OK, but which TD titles are worth your time--and cash? Here's a roundup of my five favorites. It's by no means a definitive list, but I think fans of the genre will enjoy them all. Bloons Tower Defense
Balloons. Monkeys. Darts. Nearly everything from the beloved Web-based classic appears in the iPhone version. The controls are a little finicky, but if you want to introduce young kids to the world of tower defense, this $2.99 game is the one to get. Navy Patrol: Coastal Defense
Though the learning curve is a bit steep and the onscreen action can get a little cluttered, this naval-themed, open-path TD exercise offers some of the most in-depth and challenging gameplay I've found. And the $1.99 purchase price includes new maps as they get added to the game.… Read more