Nihon Falcom announced Project N.O.X, via a new teaser website. The site has a countdown which ends in two weeks, on December 19.
The teaser site shows a girl carrying what seems to be a hatched egg and the mysterious line: "I had a Dream, found out the Truth in a prison called "cradle"... "
My personal guess is a new action RPG standalone title, but sporting the name of one of their old franchises. Basically, something like a Tokyo Brandish or a Tokyo Sorcerian. Meanwhile, most Japanese Falcom fans on Twitter are expecting a new Xanadu game. Probably because of the X in N.O.X. A new Gurumin game would be awesome too, but that definitely doesn't look like Gurumin.
The site says "2019" so whatever Project N.O.X turns out to be, it should release that year.
Nihon Falcom is one of the oldest JRPG developing studios and was a pioneer in the '80s when it came to PC JRPGs, thanks to high-quality pixel-art, animation, and soundtracks. Most of the studio's games release worldwide now, for both consoles and PC, and are quite recognized, as the studio managed to keep producing very high-quality games over the years.
Nihon Falcom previously teased it's working on a new project(s) unrelated to the Legend of Heroes series.
We'll know more about Project N.O.X in two weeks.