Tiny print at scale. I feel like I say this with almost every entry, so you're not in bad company there. It's especially a shame here because the layouts are so clean that it feels like it should be readable. My sad old eyes just can't pull it off though. Onward.
The cover is clever. It does everything a cover should be doing, but does it in an atypical way. The name byline is used in a way to seem like the name of a series. Since it indicates book 2, this is reinforced. Being level 3-4 implies it even more since someone looking at this would assume a first book would be level 1-2. Kind of fun how it all goes to reinforce the idea this was a legitimate book in a series pulled strait from a shelf. I have no idea how intentional that is, but it's what I get from it as a vibe.
The story setup is clean enough. Gives an idea of wrongness, duality, and theoretical goal. It's not really forcing anything on players, so that's also a positive for me. They can chose to back away if they want. Below that, the large number of creatures is surprising for the page count. Most people manage 3 or less due to space issues. It's a little odd getting them before anything else, but makes sense when considering the layout of the final two pages. Speaking of layout, this looks very professional. I wouldn't be surprised to find out there was a team of several people working on this entry.
That professional feel follows in the interior pages. The mirroring not just of the images, but the layout is peak design choice. I don't find much to say until I get to the Rule Engine. Since it says it is continuous, I imagine there are a ton of rules already. How are they enforced? Is it just expectations and punishment or do they literally alter the laws of the world within this tower? I can see the latter being difficult for players to follow, but the former meaning an almost immediate failure by someone in any given group.
Encounter 3 for the order side implies it is a punishment, but all of the upgrades have positive results for the most part. A longer list of encounters and upgrades would serve well if you expand this. Maybe a rule where too many upgrades mean a loss of what makes someone human. A slow degradation of their soul so to speak.
On the Chaos side, you use 'upgrades', but then later in the very first entry you use the word mutation. Given the concept of order vs chaos, I think calling the changes on this page mutations for the table would have been better as well. The flesh pool notes adding random body parts, but that implies extra random limbs, eyes, etc rather than the elements noted under upgrades. Uniformity of word choice would go a long way on this page. No major complaints otherwise about what's on the page.
Taken as a whole, it's very polished and offers a strong baseline to build a game around. If the complaint I have is 'I wish there was more' you are doing something right I suppose. With the number of creatures at the start, the towers feel painfully small. I think this is one of those entries I would highly encourage the creator to expand on. A larger document size to work with is going to do wonders for making this into something absolutely amazing to run. Even as it is, it makes good use of the limited space and well worth a read.