I still haven't finished the game. I've had to force myself to sit through much of the first city. It's just not engaging enough on its own merits.
Major Problems
* Boring Characters: most of the characters in this game add very little to the experience. Having been warned about Aligern and Callistege, I decided early on to drop them and get Matkina, Erritis, and Rhin instead. In theory, I have the best cast the game has to offer, yet even so, it feels banal, which a Torment game never should. Again, we have the 'ask me for a lore dump of my entire life' conversation style, and once again it has the same effect as it did in Pillars of Eternity and Tyranny - that is, talking to your party members feels more like an up front chore. This is made worse by the fact that they rarely have anything significant to say about what's happening around them, and too little happens to them, which might make them stand out. The fact that you can use them to pass skill checks might be a down side, in this respect, as it takes away from a sense of independent agency and removes any possibility of the player being appreciative of their help. The characters are more like tools than persons.
* Uninspiring Quests: almost all the quests in the first city have a messenger structure of the form: "Talk to A. A tells you to talk to B. Talk to B. B tells you to talk to C. Talk to C. C tells you to talk to A. Quest complete." You can replace 'talking' with 'interacting' in cases where it involves objects. Most of your time, as such, is spent traveling from one end of the city to the other. This is not only time consuming, but it does fuck all to keep interest. The lack of innovative quest structures can be excused in other CRPGs by falling back on tactical combat. But this can't be done in Numenera due to the combat being bad. Thus you're stuck with a game that has terrible combat, on one hand, and poor quest design, on the other. That is the entirety of its gameplay.
* Tedious Writing: it is very, very easy to lose track of what the hell is going on narratively in a quest, and a lot of that is due to the overly descriptive and tedious writing. But blame is also to be placed on the setting for its anything goes attitude towards logic and consistency. Near the end of my stay in the first city, as I was wrapping up my quests, I've had more than one occasion in which I simply could not remember why I was doing what I was doing, probably due to the fact that I didn't pay enough attention to the dialogue text from previous sessions. The sheer overloading of the player with Numenera lore contributes to this effect, as a quest to insert a Blerbuglubage into a Aeeniertic Viereaxxa to cause Mneiesisi is a lot harder to keep straight than a quest to stop local bandits from attacking merchants.
I can't even be bothered to write about the minor problems and issues that I experienced. Instead, I'll just say that this game manages to be even less engaging than Pillars of Eternity and Tyranny, which is an amazing achievement considering I was not all that engaged with either of those games.
As for positives, like most people I found a few stand out moments, though almost all of them were emotionally manipulative:
* The robot underground that wanted to create its own children, but kept failing
* The minor quest involving fishing for Crooked Qeek
* Rhin's brain damage and her interactions with Ahl
I also liked the fact that you could avoid combat much of the time, which made those few cases in which you couldn't, all the more annoying.