I've wondered how that Eternal Ring game was...
Have you also played Shadow Tower, Burningdoom?
I haven't tried my copy yet, but - I seem to remember hearing that it was very similar to the King's Field games.
Also, how is KF: The Ancient City on the PS2, what's its story about, and how (and how much) are the different games in the series 'connected' to each other?
Shadow Tower is prohibitively hard. I've tried multiple times to get into that game, and can't get much further beyond the beginning area, each time. And I'm a King's Field veteran. Those games aren't exactly a walk in the park, either. Unless you're just hardcore, I'd stay away from Shadow Tower. I've heard that Shadow Tower: Abyss on PS2 is better, and easier. But it was only released in Japan.
In the King's Field series, the first game (Japan only) and the 2 releases on PS1 in the U.S. are all loosely related. But you can easily play them on their own without knowing a thing from the other games. The Ancient City is a standalone game. And it's a fantastic addition to the series. I've played through it a few times. Obviously it's gonna have upgraded graphics, being on PS2. And it's a larger game. But it has that same sense of exploration, loneliness, and desolation.
Eternal Ring, so far, seems like the easiest game of all the From Software RPGs (so far at least), that I've played. So if you haven't played any of them, that might be a good place to start.