Very good game, simple, easy to get into, and rather fun. However, like most people here there are a few things that I feel should be brought up:
As I suggested a long while back for GearHead, a back button would be nice in character creations so you don't have to start over from scratch if you slip up somewhere.
A way to check your character's stats in battle without going to "change equipment" and losing a turn.
Acid Weapon may need a bit of balancing as it can be stupidly powerful by the time you get it (For example, my ranger became a one woman army with it on, dealing six hits of 1-8 damage per attack (3 normal attacks, and 3 from the additional acid damage), and with three chances to paralyze the enemy they're quite prone to getting stun locked, rendering even big enemies like dragons powerless and hardly a challenge.) and it barely costs any MP to use.
Thieves have... Dubious usefulness, since traps usually aren't much of a threat in the first place, you can simply use a bard and get magic to start off, or take thief and then on the next level-up swap to a new class with better equipment options/spells (In my first run I made my thief into a necromancer rather quickly). Really, you can replicate a thief with better equipment choices by alternating between bard and ranger (and you'd get both air and earth magic as a bonus) just as easily, since there are no real penalties for multi-classing other than perhaps stunted shard gains, atleast that I noticed.