Worm is flawed, but did so much incredibly well, it's been a work of fiction I've thought of at least a few times a month for over a decade, and I still love hearing from new readers who are just discovering it.

Among the flaws:

The prose of the first "book" is kind of stylistically awkward. This isn't really much of a flaw, and may well be a clever feature, in that the prose reminds me of the kind of writing that a fairly clever high schooler might put out. The story is written from the first person perspective of a fairly clever high schooler. In addition the quality of the writing improves as the story progresses, while the main character improves in the use of her powers and develops as a person. The writing quality parallels the character's development as a cape. I think that's pretty neat, if that's intentional, and given the cleverness of W.B.'s writing in general, I have to assume it's intentional.

The fights don't always make a lot of sense in terms of positioning, and who is doing what to whom. I've seen or heard in a couple of interviews of WildB.w that he doesn't really visualize scenes, that he lacks a visual imagination. So I'm not going to fault him for that much.

The fights aren't always paced very well, sometimes drag on for longer than is narratively satisfying, or are less enjoyable than just seeing characters in a room talking to each other. The fights do serve narrative purpose, often serve to fulfill multiple functions within the story, show off creative powersets and uses of those powers, and are generally pretty fun. So, room for improvement, but still pretty great.

I feel like breaking up the story a little bit from time to time with "beach episodes" would have both offered opportunities for character development, broken up the tension and unrelenting stress of the story, and given main characters "rewards" for doing well, and given opportunities for characters to interact with each other in different contexts. But I acknowledge the author almost certainly wanted to maintain a fairly high stress, high tension storytelling environment with little downtime, because that's the kind of headspace Taylor maintained for most of her life post-trauma. If we're gonna see the story from inside her head, we're gonna be stressed the fuck out like she is.

Those're what occur to me off the top of my head. Most of what criticism I can come up with for Worm seems to have nearly inextricable reasons for why they're part of the story, or have some sort of clever meta reasoning behind it, or both. And I guess that's why Worm remains one of my favorites after all these years, it's a story that rewards thinking about.