Hi!
First of all I must congratulate the dev team on a job well done. This game really feels old school in the best ways possible. That said, I do have some complaints, mostly due to trouble I had in solving several quests.
As the game has no checklists and pointers and thank God for that, it relies on dialogue for clues as to where to go and what to do and that is certainly welcome and immersive. However, I feel like at several points this wasn't handled well enough. I'll talk about cases I noticed in my first playthrough.
First, the Look for Cornell quest. While I later noticed that Tanner mentions that I should probably look for the help of one of the oligarch factions in Core City, this is quite an offhand remark. Asking around Core City I learned that Cornell's gang members have been seen around docks, so I went to the docks and figured that they must be hiding in the sewers. Needless to say, I spent many hours running in circles around sewers, discovering the very place that will later end up being Cornell's hideout entrance, but since I wasn't sent by the oligarch I couldn't get to him. Which I didn't know. In my opinion, it would be nice if the requirement to join an oligarch faction is more strongly stressed out. It was exactly because the game relies on clues and hints to point the player that I spent all those hours searching around sewers in vain, so making it clear that in this case it is not possible would make sense. As it was I had to consult google which is always an immersion destroyer.
Second, in the Deep Caverns I had several issues.
For starters, Leo's quest to find the knife. The whole at the entrance to the complex instruction felt very vague since "complex" could mean just about anything before the player figures out the exact nomenclature. As this is the quest that should be done early on, this didn't help. I ended up finding most of the missing parts for the gate mechanism, wiping out Tchortist base and reaching the gate itself before actually finding his damn knife. To make matters worse, since for a while I thought entrance to the complex might mean the main gate I came through after talking to Six, I searched that map and... found a shiv. And happily ran back to Leo. And then felt very disappointed.
After that, about opening the gate, I had to consult google again about removing the organic material. This was messy all around. First, Leo gave me the clue that there's a machine near the warehouse district where I should start looking. Sure, it was there in the closed off building, but I couldn't open the door. Of course I couldn't do it because the power was down. So I ran back to Arke station to check if I forgot to turn anything on. List was showing that everything I could power up was powered up. So I left Arke and went back to Hollow Earth and kept running in circles trying to figure out how to get inside or if even that is the place where the machine is. After hours of this, google told me that it indeed is the place and that I need to power it up from Arke station as I originally thought. But I could swear there was no option to power up anything extra last I was there. Turned out that the options that would go over 100% are simply omitted from the list. Which made me think they didn't even exist. So sure, when I powered down the residential area, new line appeared allowing me to power up Hollow Earth main complex. When I reached the console first I must have clicked on whatever, which eliminated the other options, which I haven't noticed on first glance, which made me think that options presented are the only options available. It would be nice to see these things even if there is not enough power. That there are lines that don't work (south elevator, prison, etc) only reinforces the notion that the options visible are the only options available.
Then we come to opening the gate. Fixing it was straightforward and clear. But removing the organic material much less so. Sure, I finally powered up Hollow Earth complex and opened the door to the closed building and found the machine Leo talked about. But I found no clues what to do about it. So I just stood there, slowly stacking Eye of Tchort, trying to figure out what am I missing. After a while I concluded whatever I'm missing is on google and yeah, learned of the mushrooms. Now here it's possible I missed something among the chat messages of Biocorp scientists in residential building, however there's just so much of it there that I must ask to be excused for forgetting about potential biocidal mushroom talk. I remember some talk about mushroom forests, but can't recall if any mentioned that deep inside it there's a place where one can find component for grenades. If so, my bad, but still would be nice to clarify that bit somewhat further. I also remembered later how Six told me that there's something in the mushroom forest that Tchort's creatures seem to be afraid of but not only is this not exactly clearly telling me what I needed to know, but it was told before I even entered the whole complex and while I was overwhelmed with all the information Six gave me because I had no idea of the things he's talking about.
EDIT: Forgot, that I have to get high on spore infection to reach the pulsing root was also kinda weird. Leo literally says he got high on those and woke up in a strange place but it doesn't make much sense that this is the actual way to reach anything, sounded more like a joke. It's very counter intuitive to stack up a debuff on purpose. I literally had it happen by accident because I'm just too skilled at dodging things that place stacking debuffs on me.
And finally, I had perfectly no clue what to do with Mutagen puzzle. I read the chat where one guy explains to the new guy how atoms combine, but I still had no idea what my goal is supposed to be. I read here that I'm supposed to create the Exitus mutagen, but it's not exactly hinted in any way apart from the machine rejecting it as forbidden compound or something like that, which didn't really make me think that's the thing I need. Could be my bad of course, but I can only see why in hindsight. At the moment it seemed like it's just a dud, redundant object.
Anyway, that's what I can think of now. I accept that most of the cases could be solved with paying enough attention to detail, but since I had no problem with this otherwise, it is still at least inconsistent compared to the rest of the game when it comes to clarification of goals.