If you are familiar with this game at all, this is a fantastic implementation of the card game. The AI is average, but still somewhat challenging.
The problem lies in that the game locks up FREQUENTLY. As in, every 3rd or 4th play (I am using the most recent iPhone 4G with the latest iOS). You have to uninstall and reinstall the game in order to get rid of the frozen screen.
When it does work, its fantastic - quick to learn, quick to play and very enjoyable. Unfortunately, if you have a long commute and want to play several games in a row, you will most likely be out of luck until this problem gets fixed.
Stu Skywalker about Reiner Knizia's Battleline, v1.4