I only got to play it for a few hours before I had to leave my PC to go spend the holidays with my family. I got up to the Mole People in the sewers (playing on medium difficulty).
So far, I like the attention to detail. The new sounds (love the binoculars), the changes to the interface, the increased interactivity with the environment, the characters without helmets in the UNATCO headquarters, the added gore, etc...
The new skills and perk system, are interesting but I feel like it might be a bit unbalanced. Like it's just a first pass but needs more fine-tuning (but that's just from taking a quick glance at them). For example, the stealth skill finally makes stealth really fun to play, but almost too easy compared to the original game. Now you can just walk up to an enemy and knock him out in one hit. No need to worry about aiming or bumping into him. It's really forgiving. However, enemies now react as you would expect when throwing an object, which is great: they go and inspect the source of the sound instead of just running in a random direction. This makes all the useless junk lying around really useful.
Here are a few other things I noted:
I like the new taser ammo type for the crossbow. However I was really surprised when an enemy's head exploded after I mistakenly fired a normal dart instead of a poison dart at it. Is that working as intended? If so, that seems to be a tad overkill. Looks like something a shotgun would do (which I haven't tried). Also I suppose the game wasn't intended for enemy body parts to be removed so there's just a hole in the model where their head should be. Is that a technical limitation or a bug on my part?
I also encountered a few graphical glitches, mainly in the Underworld bar, like some weird flashes in the environment. The same thing happened when aiming the flashlight at certain items in the environment (like the closet near Carter's shop). I also had a problem with food and drinks. After a while I couldn't consume them at all anymore (the red "you're full" message stopped appearing). Also with the medbots being limited to two uses only, choosing to unlock the medbot in the Hell's Kitchen clinic seems like a huge ripoff.
Now for the changes to the maps. I'm actually torn on this one after playing Revision. I know you're not gonna like that but I preferred some of their maps over yours (granted I haven't seen the whole game). Some of them simply offered a higher visual fidelity than yours (well the originals really). I like your version of Liberty Island better, theirs was too dark and needlessly bigger. However, I liked their version of UNATCO better. Going back to the original, it just seems really grey and boring. The same goes for the first part of Hell's Kitchen. After playing through Revision, the original feels so tiny, cramped and dull.
These are just my honest first impressions, I'm not trying to be overly critical. I know you had troubles finding beta testers so maybe that explains the glitches. Do you intend to keep working on it or are you satisfied with its current state? Anyway, I'm looking forward to spending more time with it as there's just so much to discover. I'm especially curious to try out the higher difficulties as medium seems a tad too easy.