Good Bad Bug: There are two particularly famous ones. The first being the "Jump Cast" glitch where by jumping and then rapidly shortcutting to a spell, the magic user you're playing as would rapidly cast said spell for little cost, making certain battles much easier. The other is the "Move Scroll" glitch where by using the scroll feature on your skill lists when they had more than one page, allowed you to access attacks and spells that the character normally wouldn't be able to use. Having Reid with Prism Sword for example, a spell which is only usable by certain bosses. Sadly, the first glitch was fixed in the PSP port, but the second one remained, surprisingly.
Growing the Beard: This is where the Tales series really started to pick up, particularly with the battle system. Things were sped up considerably and all spells are now performed in real time, allowing you to chain your artes with the mages rather than have them serve as damage and distraction. The game also introduced a degree of character customization in the Craymel system, two worlds with considerably different world maps, and much more character development. Tales of Symphonia and Tales of Rebirth are much more obvious examples of beard-growing in that the former started the Deconstructor Fleet and the latter started making them Darker and Edgier, but they both, in turn, owe a lot to Eternia.
So Bad, It's Good: The voice acting in the EU version of the game ranges from "They at least sound like they're trying" (Reid and Meredy), to utter lack of care territory (nearly everyone else, with Farah being the worst offender.) This is usually very funny and hammy, although some people get annoyed that Farah's VA still isn't giving a damn even during her bigger plot reveals and emotional moments.