The fundamental subject-matter of literature is difficult loves: problems that matter deeply but are insoluble. By this standard, Bee is the most literary CYOA that I've encountered. A coming-of-age story about impossible parents, limited means and awkward emergence from isolation, it put me a little in mind of I Capture the Castle (which Emily tells me she hasn't read).
Rather than being structured around a strict linear tree like the bulk of stateless CYOA, Varytale encourages modular design more akin to RPG gamebooks or Echo Bazaar style browser-adventure-RPG games. Bee is structured around the passage of the year, with different events becoming available at different seasons; age, the state of your stats, and previous events also determine which options are available. A number of sections can be repeated with variations, but (more so than its antecedent Echo Bazaar) these are things whose repetition makes sense as narrative and as reality: chores, seasonal religious festivals. The fragmentary nature of Varytale stories is very well-suited to the retrospective style, with its assembled incidents of memory.
It should scarcely need repeating by this point, but Emily writes consistently sharp, telling prose. The story would not work without it.
One of the game's strongest points is how successfully it evokes the particular intensity of the aesthetic sense emerging in adolescence, the discovery of a transformative power, burning in isolation, standing out sharply against the world of drab concerns and tired formulas. The most prominent parts of this involve the protagonist mapping out for her own feelings about Christian ritual and the English language, but also in the seasons, in the contemplation of an emotion, in the elusive moments of family happiness. It's a story about learning to appreciate things deeply, and how to negotiate for a better deal, and reconciling the two. It's about the realisation that you're smarter than your parents. Like much of Emily's work, it's about the pathos of limitations, about lofty ambitions that will inevitably be diminished -- you're told from the outset that you will not win Nationals. (Despite the competitive framing, and in line with the Varytale ethos, this is only slightly game-like; character stats are tracked loosely, and while not every node can be found in a single playthrough, there is not really any challenge per se.)
It's also about an interweaving of shame and bristly pride; at its most documentary, Bee becomes something of an account of the culture and experience of homeschooled children. It's neither an attack nor an apology, though it has definite elements of both; it paints a more nuanced picture of homeschooling than is usual from either its advocates or mainstream critics. One obvious effect is that the protagonist has no friends in the normal sense: the listing of known characters makes a distinction between family (too basic to list) and Acquaintances, an uncomfortable and lukewarm category that's confirmed by the text. (Of course, much of this is because the protagonist's intellectual development is far in advance of everything else; it's easy to think of her as being considerably older than she is. For a while I had the vague sense that the story dealt so slightly with sex and romance because she was from a repressed religious family; but once I actually articulated the thought, I realised it didn't hold up.)
(As a technical note, I first played this when play was restricted by Story Points, Varytale's equivalent of the Echo Bazaar candle. Bee is, at present, no longer thus restricted. Generally speaking I loathe the candle system; it's horribly anti-player. But I'll admit that its artificial choke on pacing does affect how one reads, and offset the distinctly CYOA-ish temptation to hurry through the text and to get to options.)
It's a broad truth in IF that the best works dealing prominently with Christian themes are written by non-Christians. Cana is the exception.
The game is presented (very loosely) as a late-Victorian translation of an apocryphal account of the Jugs of Cana, better-known as the water-into-wine miracle. As an obscure servant in the house of the bridegroom, you're tasked with finding more wine for the party and, eventually, in setting up the miracle.
The main thing the game depicts is not setting or plot or puzzle or individual characters, but a community: a community composed of individuals, many of them basically dissatisfied, most with diverging interests, full of conflicts great and small. Fundamentally an attractive community, full of kind, generous, intelligent people, but one which you are not quite a core member of. This goes a long way towards making it feel alive, rather than a tidy little parable.
Gameplay-wise, it's old-schoolish and not immensely intuitive. There are multiple solutions to certain puzzles, which have an impact on the general story, but interaction is not the central interest of the game. Some lines of inquiry rely on quite specific knowledge of the original text, and others are counterintuitive. There's a substantial hint system. Use it.
The game's core moral dilemma is, intentionally, trivial. (Spoiler - click to show)Joshua (Jesus) asks you to fetch some water; it's emphasized by other characters that you must do exactly as he says. But shortly thereafter, you have a choice: in order to save a child's life you have to disobey the literal commands of Jesus. The triviality is the point: anybody with the most rudimentary ethical sense can see the right answer, that literalism can't be allowed to trump straightforward ethics.
The approach to the rest of the story takes a similar attitude: it can't really be construed as an attempt at a strict historical retelling. Instead, it treats the text, story and history as juicy story elements rather than hard facts, and indeed in many places it's conspicuously ahistorical. Characters appear who are unlikely to have been around before the start of Jesus' ministry -- but then, so is the freaking Ancient Mariner, a guy who seems carefully chosen for maximum historical inconsistency.
(In the interests of full disclosure, I should point out that I've played an RPG campaign with Chris as the GM, and he took a highly similar approach there: a joyful, loving appropriation and blending of every story in sight, to the point where navigating the game became as much about interpreting, recognising and playing with the references as about in-character decisions. This led to one of the most fun and sustained RPG experiences I've ever had, which inescapably colours my experience of Cana.)
There's a certain kind of literary Christian who seems more invested in the aesthetic potency of Christianity than in its truth or goodness. Borges loved Christianity mostly because it led to Dante, Chaucer and a thousand strange and beautiful theologies. Cana does not quite fit into this model, though it can certainly be read in that mode: miracles and their significance are not really its central interest. (Indeed, Jesus doesn't quite seem to see the point of the miracle, which is fair enough: setting a party up with booze isn't quite the same order of things as healing the sick.)
Of course, all this presupposes that you actually get a decent proportion of the references. Your actual religious beliefs aren't directly pertinent to whether you enjoy Cana or not: more important is a textual interest in the Gospels, and a sense of humour about them.