I'll give the credit where credit is due: this game has great characters and world-building. That alone is enough to make the game tolerable. But that's really the best I can describe it.

In terms of the gameplay, it's just awful, and that's not just my opinion. I don't know much about DnD, but AFAIK it gives the player a lot of options to basically make them feel like they truly inhabit a world, where they have as much free will as they do IRL. Looking at Planescape from that perspective, it is extremely linear. In fact, I'd even say it's more linear than the streamlined KotOR clones of the 2000s.

Most of the NPCs you talk to are lore banks. "Dialogues" with them are pure exposition dumps. In most cases, when you are given dialogue options, you have one or two. When there's more, in most cases the extra options are completely non-viable. For example, being aggressive will always get you killed, even when you're playing as a Fighter class, except for when you're dealing with bums and lowlifes. In my opinion, it would be best to just not have those options in the first place.

If you genuinely try to immerse yourself in the world and role-play as a sane, rational person, you'll just not move the story forward. In most cases, the most rational thing to do is not to speak to an NPC or not to do their quests. But the game still forces you to, while pretending like you have a choice. It ends up being the case of clicking every dialogue option until you find the right one, even if it makes no sense to you.

In between the dialogues, there's little to no actual gameplay. You run around talking to NPCs and occasionally fight. The combat is extremely simplistic and not fun. You start with no skills, armor or proper weapons, and several hours into the game you still have none of that. And even if you choose to play as a fighter (which is the class you start with), you're too weak to solve any significant problems in the game through force. The inventory management and the leveling-up are just as simplistic as the combat. The worst thing is, while being so weak, you still have to constantly run through hostile environments with respawning enemies.

Most people who praise this game will also acknowledge that the gameplay is flawed, and the main selling point here is the story. And this here is why I never take gamers' advice on story anymore. Most gamers don't read any good literature or watch any arthouse cinema; their idea of a great story is a Marvel movie. I've been conned into playing through the entirety of Star Wars: KotOR 2 by people saying it has a deep and philosophical story, which in reality turned out to be some vague ranting about the (clearly misunderstood by the writers) concept of the Force. I've been hearing the same things about this game, and it's written by the same writer. I'm not gonna spend 30+ hours on this one too just to be disappointed.

In my experience, great stories in video games tend to be great from the start. Take Deus Ex for example, a game in a pretty similar genre. Every piece of written content and every interaction with an NPC there carries substance beyond just world-building. Characters discuss relevant political and philosophical themes that engage the player intellectually and emotionally. All the books, newspaper clippings and emails carry valuable commentary on late-stage capitalism, militarism, autocracy, the co-option of technology by the powerful elites, philosophical musings upon the impact of technology on human identity and freedom, etc. I legit walk around quoting Deus Ex, because the quality of its writing is on the level of actual art. And this quality is consistently displayed from the very start.

But what actual substance did I get from 4+ hours of playing Planescape: Torment? Well, I learned a lot about Sigil, the city of doors, and the reputation of Pharod, and the warring factions underneath the city: the rat(-people?) and the undead. This is all superficial stuff. Where's the beef? And all that I had to learn between terrible gameplay segments.

I honestly went into it thinking "well, at least it won't be as bad as KotOR 2, because that game is broken", but at least KotOR 2 is built on the solid template of the first game. And, in fact, I can't really say Planescape: Torment is not broken. Perhaps, it's less broken, but I've encountered some instances of incorrect dialogue-chains, and one time I accidentally soft-locked the game. It was when you have to get Soego out of his room and snitch at him to Hargrimm. I suppose I must've gotten him way too far from his room, because then he didn't reappear in the "cutscene" where Hargrimm is scolding him. So the "cutscene" just stuck and there was no way out of it other than Alt+F4'ing out of the game. It's a good thing I saved right before that. Which btw the game often will not let you do for no apparent reason.

In the end, I felt like I did have some interest in continuing, purely out of curiosity based on the character relationships. But there was a segment where I did not know what I was supposed to do. I talked to all NPCs available, clicked on all dialogue options, and still had no clue. And I was so tired of the respawning enemies, that the very idea of running back and forth between these NPCs felt exhausting to me. I think, if this game truly had the amazing story everyone keeps raving about, I'd probably be willing to suffer through the horrendous gameplay, but clearly I am not.