This was the game that started it all. It was the first game to have full voice-overs for all of the characters, as well as the first game to have a vocal opening (which would become a staple in the series). Being released near the end of the Super Famicom's (the Japanese name for the Super NES), it had graphics that outmatched most games released before it --- Star Ocean would be one of the few games that would top it (both games were done by the same team).
The game included a action-based battle system, which was a rarity outside of games such as the Seiken Densetsu/Secret of Mana series, although the battle system hasn't aged that gracefully, due to quirks in the Short/Long-Range modes the player has to alternate between (techs used depend on how close/far you are compared to your enemies) --- this issue was fixed in the PlayStation remake, which used Tales of Destiny's battle system as it's base (as well as other parts of its game engine).
The game also included many factors which would become regular staples in the series, such as anime-styled character artwork in the Status menu, as well as known-series items such as techs, cooking food, and the currency of the series known as Gald. Due to this, the game has been remade/ported no less than three times as of 2007.