In Letters, you're a teenaged girl reading, tracing and clicking your way through a pile of letters from your ostensibly cool school friend Cadence after certain events have occurred.
Both main characters have solid writing chops and some wisdom beyond their years, and they communicate everything to each other by handwritten letters in the year 2008, give or take a few years. I felt this setup was a bit of a contrivance, the kind of thing that is outrageously possible in real life yet which takes a certain amount of feinting or explaining when delivered as fiction to get people to buy it. I decided to accept the premise and move on once I acknowledged I was enjoying Letters's sparky, emotional teen writing, and that I was also being prompted to think about how I was interacting with this IF. It worked for me both as emotional writing and as something with a bit of a puzzly feel, an experience I've rarely had with similarly presented IFs in the past.
I spent about twenty minutes with Letters and felt that I had satisfactorily experienced most of its content by that point, though probably not all of it. It's not easy to track which links you've previously clicked, unless perhaps you lawnmower them, or have a better memory than I do. It was a testament to the game's effectiveness that I had no interest in mowing the lawn. I was clicking particular links I wanted to click for reasons I possessed or imagined in relation to the story. Contrivances accepted, I liked Letters a lot.
More detail, with spoilers, beyond.
Letters is not outwardly gamey, but part of the blurb is a challenge – "Can you find her?" (your friend, figuratively) – and there's a certain labyrinthine quality to the link structuring. The 'Start Over' end nodes often occur after emotional climaxes or relatively drastic events. Something about them makes you want to avoid them, or just nervous about encountering them. This sensation probably emerges from a basic desire to avoid premature closure of the story. And there's a feeling that if you choose wisely, maybe you can in turn eke out wiser decisions for the characters. For instance, an ending that's not too deep in the structure and which occurs immediately after you tell Cadence to piss off, suggests that maybe by doing so you harmed the friendship so early in the piece as to preclude its development. In light of moments like this, I don't interpret the pile of letters to be a bunch of static found objects that you're going through. They feel more like your interface to a story that has an unchanging core but which you can get into more deeply if you're persistent, or sometimes deflect off if you're unlucky.
The key things I liked about Letters are that I wanted to find more ways into the story, that it wasn't entirely elementary to do so, and that there was a good balance between links that made me feel narratively rewarded for picking them and links that capriciously made the story crumble and sent me back to the (not too far away) start.
There's some tension, while reading a letter, between wanting to click particular links as soon as you encounter them, and holding off and reading the whole letter first. Sometimes reading to the bottom of the letter reveals more links that were initially out of range. Maybe they'll be more interesting? Or maybe you're effectively changing events in the story by disregarding later parts of a letter to move laterally earlier? I also like that I never entirely resolved all this stuff, and the answers probably aren't set in concrete anyway.