There are two parts to the E3 2010 demo for Golden Sun: Dark Dawn, and I got to play the adventure section of it.

You control the main character with the stylus around a series of areas that introduce you to the Psynergy powers of Fire and Push. You use Fire to destroy obstacles, and you use Push to move objects with a giant hand, much like the other two Golden Sun games. It's all stylus-controlled, and you direct the fireball by picking dragging the stylus from your character to a point in a radius around you. For Push, you merely drag the object you want to move. I had some trouble with the stylus controls, but after a brief learning curve, I was moving and firing in no time.

I went through a dungeon that showed off some more puzzles, including one where I had to jump around different areas to move statues onto switches. It was basic, but it seems to be good groundwork.