With bolstered graphics and sound, the DS version of an NES classic is riding very strong
Graphics-wise, the game is top-notch. The towns of the game have been given a 3D style and perspective. The buildings are so much improved that you'd have to rotate the camera just to find the door to the weapon shop. The battle are much better-looking, with most of the monsters having detailed animations while the trademark monster, the slime, attacking in pure 3D.
Regarding sounds, they're very pleasing. The music is a vast improvement from the original NES version. Even the title screen theme is played with a full orchestra. The sound effects are not too shabby, either, the series' usually battle cries and magic incantation
Control-wise the game is very good. Although the touchscreen of the DS is not used in any way, it is really not needed to move the party around and move through the various menus. As mentions, you can rotate the camera while in towns and castles by pressing either the L or R buttons, allowing you to get a better view of your surroundings.
As far as gameplay is concerned, this is where the game shines. The game is separated into five chapters, giving the storyline an epic feel. Also, there is a substantial amount of post-game content after you intiitally beaten it, adding a ton replay value. The game even has various casino games to take a break from the usual level-grind, ranging from the traditional Poker and Slot Machines to the betting on the monster battles, where it's monster vs. monster and controlled by the A.I. to determine the results.
Overall, Dragon Quest IV: Chapters of the Chosen is a very solid RPG that should not be missed by both fans of the series and fans of role-playing games alike.