Just plain great.
The story is excellent. It is told very well too. there are so many endings(more than 10 different endings!), that you can have a different playthrough even after you finish it. You start out as Chrono, a young swordsman who is thrown 400 years into the past by his friend Lucca in a freak accident working on her new experiment. He isn't sent there alone, Lucca sent Marle, a mysterious girl Chrono met at the fair, along with Chrono. They eventually get back to their time after going through(again) what Lucca calls a "Gate" to the year 2300 AD and learned the truth about a parasidic monster named Lavos who will destroy civilization in the year 1999 AD(glad this is a game or we would be in trouble), and leave everything in ruins. This game has a few shocks, but many twists(people aren't who they say they are, etc). There is a lot of character development(even with the minor characters), which will sometimes surprise you on how important their role actually is.
This game is on the SNES, so don't expect great visuals. The graphics are pretty good though for a SNES game. The areas(like the domes in the year 2300) look like toys in the world map, but when you enter one, it looks very detailed(like it was in a comic book).
The sound is very clear, and each track goes with the mood of the event that is currently happening at that moment. As you travel through time, the world map's song changes(for example, the year Chrono, marle, and Lucca are from, year 1000 AD's track is more light-hearted compared to the world map from the year 2300 AD. 1000 AD's track sounds more renociansse-like, while the 2300 track is more dark, futuristic, and grundgy). The character themes are good too. My favorite is Frog's theme, but I think Robo's theme is catchy.
Before you start the game, you have the choice to make it Active(ATB) or Wait, which is mainly a full turn-base gameplay. In active, your opponents can move and attack while you choose to use techs or items. Techs are special attacks and magic. They go by the rules of magic in every RPG game made(you use a tech, you use some of your MP for the Mp cost, and the tech activates). There are dual-techs which are a combo tech done by 2 or more characters(think a combo attack), which are very helpful at times, and are fun to watch.
This game has to be one of the greatest games ever made. It has a great story, good character development, and fun things to do and see. From start to finish, you will never want to put it down. if you are a RPG fan, or a hardcore gamer, this is a must buy.