I saw a used copy of Trace Memory at the game store for $10. I took the empty box to the counter, and they started digging around in the drawers to find the cartridge. They couldn't find it, so the store manager offered to sell me a new copy (normally $20) for the used price. Whoot!
It's reminiscent of the old point-and-click RPG games from the 1990's, like Space Quest or Indiana Jones and the Fate of Atlantis. As you walk around, you're presented with scenes and you can point and click to explore or use items. There are several puzzles that involve various DS features like the microphone or closing the cover. In this game, you play a young teenager whose father disappeared several years ago. One day you receive a package and an invitation to meet him on Blood Edward Island. When you arrive, you discover the ghost of a young boy who died there 57 years ago and who has lost all his memories. You have to explore the mansion and try to help the boy regain his memories, find your father and discover the secret of the Edward family.
The story line is rather interesting, but the interface is a bit clunky. It takes too many clicks to accomplish certain tasks. The game also sometimes won't let you pick up items until you discover why you need them. (When I play RPGs, I pick up everything I can get my hands on, no matter how weird or seemingly pointless the item seems at the time. I walked around a good chunk of Fate of Atlantis with a ham sandwich in my pocket.)
Phantom Hourglass is lots of fun. I am rather disappointed that they chose to only use the touch screen for movement and attack; the D-pad doesn't do anything except open menus. I fell off platforms way too many times because of the touch screen. Attacking monsters is pretty easy, generally you just tap on them with the stylus and you automatically attack. The game isn't too difficult, most of the time, though there are a few bosses who can be a bit tricky. The Temple of the Ocean King (which you have to visit 6 times!) is rather hard, since you're on a clock and have to deal with unkillable enemies.
The biggest problem I had with the game is that the fishing instructions are ALL WRONG. The game makes it sound like you have to keep making downward strokes on the touch screen to pull the fishing rod back. I tried this for a while, and it was practically killing me to haul in even the smallest fish, and anything bigger than a couple feet would always get away. I Googled around to see if there was an easier way, and learned the RIGHT way to fish. You make ONE downward stroke, then hold the stylus at the bottom of the screen for as long as necessary. That's it.