Bumping this just for those that haven't seen it in the store.
Only played enough to find Otto in the cave. So far battles are super easy, but I expect them to get harder later. You level up surprisingly quick in that first cave, so it's worth doing those initial easy fights.
One thing I wish it had was a better indication you are going into battle. Right now, there isn't even a sound or a flash, just switches you to battle mode. Sometimes when I unexpectedly cause my character to stop, I pause, thinking it was about to go into battle.
Besides the menu being plain iPhone interface, and a lot of hitting back buttons, the rest of the app has a nice slick iPhone presentation.