Thanks for your feedback.
You're right about the AI. There's none, actually. I wanted to make them, but I didn't have the time, so all the enemies are playing randomly.
I'll think about another battle representation too. In fact, I figured the dialog box on the bottom may catch the player's attention exactly when he should watch the top screen. And that's why I fixed this in a rush by adding the "watch your HP" text. ^^'