So, I finally played through Planescape: Torment this week. Lots of thoughts! It's a good game, it does a lot of things I really appreciate with the storytelling: the extent to which you can dialogue through rather than fight through key moments in the game, and the game tries to make that an equally valid outcome, is really interesting. I think it was nice for me to have a game that used the planar cosmology on its own terms, and whilst I really could take or leave the planar stuff in D&D proper, actually Planescape as a setting in its own right offers a lot more interesting high-concept possibilities that I don't think you get just from its relationship to the Prime Material Plane being the core focus. I think I can now actually remember that devils are baatezu and demons are tanar'ri, a distinction that two whole Baldur's Gate games completely failed to din into me, and I might be able to remember which of the Githyanki and Githzerai are which too on a good day.
Narratively, bits of the setup oddly reminded me of the first witcher game - "amnesiac back-from-the-dead scarred protagonist with gruff voice and mystery cosmic-level enemy goes adventuring and is unexpectedly and inexplicably attractive to women" is apparently a whole genre. The companion characters are generally well written and have good plot arcs: Dak'kon's was probably my favourite for the writing, I enjoyed Nordrom a lot, and I thought Falls-from-Grace was conceptually a SUPER interesting character who I'd have liked them to do more with. Annah was a bit stereotypey but rescued by the delightful voice acting. In general, the game kind of struggled with its women characters in a very "this world feels written by white heterosexual men" kind of way, to the point where it felt in-your-face and weird to me, a white heterosexual man. It's not that the writing was overall bad or that there weren't some good concepts, but some quite creepy bits are played mostly for laughs, about 40% of the random women NPCs are "harlots" standing around on street corners, almost all of the well developed women characters are in love with the player and the one who isn't is a literal personification of lust, etc. Artefact of its time, of course, but I did find that noticeable.
There were some super nice touches though. The early quest where you have to get your companions to believe that trees ought to grow in a certain area I absolutely loved: clever way of getting more character interaction, making a really important point about the setting being shaped by belief, and providing some tonal stuff that provided a level of hope. It would have been very easy to try and make Planescape far too grimdark, especially given the backdrop of the Blood War and the player's ultimate fate and so on: I think they avoided that quite well. I also loved the Modron Maze, the silly drops of "A Clue!" and things like that which emphasised that they hadn't got the concept of a dungeon quite right were very enjoyable. The pacing of the storytelling is very good as well, there's one thing which feels a very unexplained plot hole by the end of the game but given the complex weirdness of the plot that's not bad going.
I did my playthrough as Neutral Good, which I liked (though it was annoying that there were e.g. LG restricted items but no NG restricted ones, NG shouldn't just be treated as a halfway house alignment). I'm not sure I felt there was so much other content there that I was keen to do another run: the small number of companion options and relatively linear story don't give immense scope for different runs, and I don't enjoy going back to do evil or mercilessly lawful runs which a Vhailor/Ignus in party run could end up like. I'm aware there are a few additional cutscenes etc for other options I could have taken, and one or two faction moments and quests I didn't do, but I was fairly completionist (and used walkthroughs quite a bit). The fact the game only took me about 35hrs despite that felt good going, I'd actually quite like more RPGs that don't ask for 100+hrs of my life.
So all in all I thought it was pretty good and it's a pity they didn't make more Planescape games. I think you'd have to switch protagonist to do a sequel but it felt like there were a lot of interesting things in the setting still to explore.