It's almost as non-linear as a novel, except you can't peak at anything further ahead than your current point in the game. I guess I felt excited that I could make choices in the game, but there were only a few choices that actually affected the ending. Most of those choices are in sidequests that are easy to miss (some of which I did miss. Don't worry, I watched the True Ending online). The main storyline choices are "ending that lets you keep going" and "bad ending." I wish that there had been more branches and a better illusion that there wasn't always one right choice. Maybe you need a less epic story to have multiple "okay" endings; where the world ending because of something you did isn't the default "wrong."
Radiant Historia has a fairly interesting battle system. Enemies are in a grid and certain powers can move them around to overlap, and when enemies overlap you can hit both of them at once. Also, if you hit an enemy many times in a row, successive attacks do a little more damage. You can also change the turn order to get everyone doing stuff in exactly the right order. I don't think I properly appreciated this system until a walkthrough got me to string ten attacks in succession (and I think you get more XP if you do more attacks in a row). It makes me sorry that I didn't experiment with it more earlier.
If you're a fan of JRPGs, I recommend this one, especially if you liked Chrono Trigger, but don't expect a bazillion endings.