This is a pretty good effort though some flaws exist; definitely play this instead of Final Fantasy 3 for the DS or Final Fantasy 5 if you want to play a Final Fantasy themed game with a job system that doesn't drop the ball. The graphics and sound are pretty mediocre, nothing really interesting except maybe a few familiar Final Fantasy jingles.
The story is pretty decent and it has a somewhat interesting theme on forgetting memories (to soften the blow of painful experiences, though you have to recover important ones). If you played Final Fantasy 3 and hated its execution but liked its potential, you may want to play this game instead. The characters aren't too special but at least the pacing isn't dull.
This is one of those random dungeon "roguelike" games that have the enemies on-screen without going into a special battle menu and fighting them, needing to take advantage of the positioning. (In other words, my 2nd Quickstrike RPG, Time Stalkers and Tales of Phantasia Narikiri Dungeon are exceptions due to its battle systems although they use random dungeons; think Shiren the Wanderer for DS aka Shiren's Dungeon 2 for SNES and Azure Dreams). There are a few flaws though. First of all, the loading times can take about 10 seconds (fortunately this isn't for every floor you enter in the dungeon). Next, diagonal movement is a pain on the Wiimote; you have to hold B and tinker around with the d-pad until you get the diagonal motion you want. Using B to automatically face and move diagonally would have helped a lot more.
There is also a job system in which you can have Chocobo play the roles of certain classes like dragoon or ninja. I repeat, this is a good replacement for Final Fantasy 3 because of a better job system (though honestly jobs/classes aren't original now; even Alien Syndrome has a class system), shorter dungeons, and decent bosses.