Scrappy Mechanic: Among Dragon Song's problems was the fact that running drained health. If you can get past that, you'll eventually face wave after wave of enemies that can break your equipment. Not fun.
There's also the fact that you can't choose which enemy you attack, the game having each character's AI choose their target instead and taking much of the strategy out of the player's hands. Not to mention Combat and Virtue modes, which boils down to having to choose between getting XP from a fight or items. Really, much of the combat system suffers from the designers over-complicating even the simplest, most basic RPG mechanics.
Suspiciously Similar Song: Unlike all the other games in the series, the Dragon Song soundtrack has no input from composer Noriyuki Iwadare. However, many of the songs are basically well-executed variations on songs Iwadare wrote for prior Lunar games.