DQ IV's remake on the DS looks great, and the core adventure is wonderful, but the old school gameplay can be a grind.
This is made very clear as you play through Dragon Quest IV. Square/Arte Piazza have done a great job updating the controls and visuals of DQ4, and the game looks quite good, with "free" camera 3d game worlds, nice looking enemies, detailed hand-drawn sprites in combat, some decent spell effects, etc. But at its heart, it's a very slow paced, combat-grinding-heavy, turn based JRPG. I enjoyed a good 12 hours or so, but finally just became worn down by the repetitive and slow-paced combat, and fairly generic and light story.
Still, if you're into a lighter and slower paced JRPG, it's well done and ultimately fun.
The good:
+ Great looking visuals throughout, in both 3d and 2d portions of the game.
+ Very good, lively music with decent variations through the different segments of the game.
+ Same light humor peppered through the game, and some fun, silly dialog as the game incorporates accents through phonetically written text.
+ Fairly strategic combat, particularly against bosses and their minions.
The not-so-good:
- Lots of grinding via random battles as you wander through maze-like dungeon after maze-like dungeon.
- Not much in the way of character customization outside of basic equipment choices.
- Dungeons can be very repetitive and bland both in design and visually.