I've been playing these games on Duckstation emulator and they're great fun, always thought about playing them for ages. I've beaten King's Field 1JP, King's Field 1US (2JP), King's Field 2US (3JP) and King's Field 3 Pilot Style and now I'm playing Shadow Tower. I also have King's Field 4 and Shadow Tower Abyss waiting for me with PCSX2.
Be nice about my playtimes, I tend to be really autistic in these sort of games, especially ones that demand wall-humping for secrets or even required progression, you can probably beat each of these ones (not counting ST which I haven't finished yet) in like half of the time I played them for.
My opinion of King's Field 1 is probably a bit more generous than most people's on account of me deciding to play it first (and play the games in order) rather than jumping around and noticing features missing that were in later ones. Yes it's a tech demo... it is FromSoft's very first game after being an office software company after all, but it's still a very good first outing for them imo. An example of something I would have noted as unplayably clunky if I had played 2 or 3 first is the slow turning speed, while it was a bit of a nuisance at times while playing, for me going from KF1 to its sequels showed a clear gameplay improvement rather than me struggling to adapt to something older and less polished if I had played them out of order. A lot of people on the internet when I was searching around for stuff on these games prior to playing them were saying you should play them in orders like [4>2>3>1], [2>3>1>4] or [3>2>1>4], which is very weird to me because I found that progressing with the feature and mechanics improvements they were implementing in the order they developed the games felt much more natural. Almost none of the cringe reddit posts suggested a standard [1>2>3>4] order of play, which was very odd to me. It's pretty much a standard level-based dungeon crawl without being locked to grid-based movement or turn-based gameplay, quite reminiscent of Ultima Underworld although not quite as complex.
King's Field 2 was amazing, I really liked the interconnected almost metroidvania-style 3D world space and I liked getting to grips with the layout and becoming ultra-familiar with how to traverse it when backtracking, it reminded me of System Shock 1 a lot while playing it, and then I got to the final level
where you fight Guyra literally in cyberspace for some fucking reason and I was so sure that FromSoft
must have played System Shock while developing King's Field 2, but the Japanese release of System Shock 1 wasn't until 1996 to my knowledge (King's Field 2 released in 1995 in Japan), I suppose it's possible that some people at From played a western copy of the game (1994) and that would line up perfectly with the development time of King's Field 2, but that's just my autistic theory.
King's Field 3 as HHR said above is a lot more Zelda-ish. The world isn't anywhere near as metroidvania-esque as King's Field 2, it's more like a series of varied levels connected by a tunnel each way, they don't really loop into eachother like some spaghetti maze like KF2. There is also potential to cuck yourself with certain quests because it doesn't hold your hand and go out of its way to make sure you do everything in the right order, the game has two different endings so there's a bunch of optional stuff you can do to get the 'good' ending. King's Field 3 Pilot Style is a very short Japan-exclusive press event demo disc where you play as the character Captain Silviera prior to King's Field 3, not much to say about it but I figured I'd play it just to say I have.
A very good trilogy all in all. I've read that King's Field 4 is totally detached from the "Verdite Trilogy" and is basically a reboot. Does anyone who has played it know if it at least includes references to the first three games beyond the obvious recurring Moonlight Sword?
I'm playing Shadow Tower now and the enemy designs, claustrophobic atmosphere and lack of music makes my skin crawl.