Xenogears is a cult classic RPG from the original PlayStation that is infamous for being released in a condensed state, as the developers ran out of time and money. When Xenogears was in development, it was pitched as becoming Final Fantasy VII, but it almost became another game, as it was originally planned to be a sequel to Chrono Trigger.
The information about the connection between Xenogears and the originally planned sequel to Chrono Trigger comes via a pamphlet that was distributed to attendees of the Xenogears 20th Anniversary Concert, which was translated by Lugalbanda and can be found on the Xenogears and Xenosaga Study Guide site.
Interviewer: Please tell us how you ended up as the composer for Xenogears.
Yasunori Mitsuda: At the time, we had just finished up Final Fantasy VI and Chrono Trigger, and we were just about done with Mana and other projects. So, we had started talking about making a PlayStation game. We knew we were going to make Final Fantasy VII, but we didn’t have anything set in stone beside that. When the sound team had a meeting, we talked about how there was definitely going to be a Mana game and a SaGa game, but Mana would best be left for Hiroki Kikuta-san, and SaGa would be best left for Kenji Itō. There were other teams forming, and one of them was Takahashi-san’s Xenogears. I didn’t really care what team I ended up being assigned to, but I was interested in Takahashi-san’s desire to try something new. In addition, Masato Kato, who wrote scenario, was a good friend of mine, so I had a desire to make another game with him. (Note: “I, unfortunately, know him too well/ I’ve tried to get away from him but I can’t” in an endearing way) So, I sent a request saying that I would like to be assigned to Takahashi-san’s team if no one else wanted to do it. At the time the staff had assembled, the game wasn’t called Xenogears yet.
Interviewer: It was a different name?
Mitsuda: At the time the team was supposed to be responsible for a Chrono Trigger sequel; the “Chrono 2” team. But Takahashi-san wanted to make his own world, so it wasn’t going to be “Chrono 2”.
The original sequel to Chrono Trigger was a game for the Japan-exclusive Super Nintendo Sattelaview add-on, called Radical Dreamers, which later formed the basis for a different sequel to Chrono Trigger, called Chrono Cross.
The transition of Squaresoft from Nintendo to Sony was a pivotal moment in the history of all three companies and the decisions made back then would go on to influence the video game industry going forward. It's strange to think of a world where Chrono Trigger received a sequel that was developed by the Xenogears team and the form that the game might have taken.