Chrono Trigger: Crimson Echoes boasts over 35 hours of gameplay, including many new features such as new techs, minigames, even a Battle Arena mode (similar to the one in FF7). It attempts to bridge the gap in story between Chrono Trigger and Chrono Cross.
All in all, from having played it for about 5 hours or so, it's quite well done. There are a few typos, and I've run into one game-freezing bug that I was easily able to avoid after resetting. The difficulty of combat has increased significantly from the parent title, as enemies tend to have more HP, so battles last a bit longer and use a few more resources. Crono actually speaks in this game, since he's not really the main character anymore. The game will change scenes to different characters to give everyone some facetime.
Anyway, any fan of CT should at least give this a try. Below is a RAR file containing both ZSNES (which is recommended to play it with instead of SNES9X) and a pre-patch game file. It was originally just released as a patch file, but I had trouble getting the patch to work correctly. All you'll have to do is load up ZSNES and open the Crimson Echoes SMC file.
It is really hard, though. There are lots of enemy encounters that make me want to pull my teeth out, and I find myself actually running from the more annoying battles for the first time ever playing a Chrono game.
If you ever complained that Chrono Trigger was too easy, you won't be disappointed here.
Over the mountain, in between the ups and downs, I ran into Densetsu who doth quote:
It attempts to bridge the gap in story between Chrono Trigger and Chrono Cross.
How the heck? Trigger and Cross were only very, very tangentially related.