Bionic Commando: Rearmed developer GRIN had been working on a Final Fantasy project before it was closed. Codenamed "Fortress," the artists and programmers from that studio have since gone their separate ways, and many have updated their portfolios with work from the era, giving us a clearer look at the canceled game.
User DiipuSurotu on NeoGAF compiled the work from several different sources, letting us see some striking character and environmental designs, and even some videos. Below you can see one featuring returning characters from Final Fantasy XII, and another with some test battle animations starting at the 1:32 mark.
One anonymous programmer described Fortress as revolving around a small group of soldiers defending against an invading army. The player would be tasked with keeping troops stationed and morale high enough to defend the base, and the soldiers could visit ancient temples between attacks. He claimed the goal was to have about 2200 models engaged in combat--2000 attackers and 200 defenders--all fighting without seeing repetitive animations "like bad background actors in a movie."
Here are some of the found videos: