Makes down time, in store lines or on hold with Utility companies, go by faster . Cons: It's best to turn down the volume on your phone , while your playing this game, the sound effects can be annoying . Especially at work :)
This is a really good tower defence game. Even after a couple months, I still go back an play this for long stretches. Cons: the early versions crashed a lot (though that may have been an apple OS issue). The recent versions seem stable though.
The BEST game for iPhone, in my experience. Simple. Addictive. Cathartic. It's like Lemmings in reverse. There is no learning curve. Cons: I wish there were more than just four weapons. People, make a sequel already!