Just as I started writing this, I looked up a game I was strongly reminded of while playing: The Strange Case Of The Serpent. I was pretty surprised when I saw you were the author of that as well! I was previously imagining the rise of some sort of Unity bricolage microgenre starring games like Pictures of a reasonably documented year, but I'll abandon that idea now and settle for referencing your earlier work.
Regarding The Strange Case Of The Serpent, I agree with many of @Noyb's criticisms from that thread. While I found parts of the game compelling, I was uncomfortable with the way you rewrote the events of increpare's original game. I also found the Hitchcock footage a little too out of place; it didn't mean enough in the new context of your game to fully justify its presence. While Cartas didn't make me uncomfortable, I did get a really similar vibe from its use of Lumière footage. It only related to the words in the most tangential ways, and as @BlueberrySoft mentioned, there's a lot of baggage there. I agree that the unfiltered textures have baggage too! I'm a fan of that visual style as well, but it evokes the PS1 and its contemporary games (seemingly pointlessly). Staring at that cart wheel for so long really made me wonder about that a lot.
Like others, I got a museum/gallery vibe from the game, which I liked. The basic presentation, font choice, title screen, intertitles: all of these felt really polished and visually nice to me, I would say I appreciated this aspect a lot. The section with the building façades and the rising swell of dog barks was my favourite, and I liked seeing the blue glow as the boat clipped through the mountain. Both these moments felt best as pure surrealism, I didn't really want to link them to the other parts of the game or the content of the letter.
You've controlled the pace of the game completely. Barring total player rebellion, it will always take about the same length of time to finish. While playing I thought about how often only one aspect was in focus at once, and couldn't really be sped up or slowed down. At the start, reading subtitles after the image of a cart has lost its novelty. In the middle, navigating environments while reading nothing. At the end, reading again, accompanied by imagery that I once again found inessential. I wanted to listen and read and move all at once, but I suppose there's thematic relevance to my desire for freedom that would be undone by catering to it.
I should probably mention that I failed to really engage with Cartas overall. Throughout, I found it kind of boring. For whatever reason, the words in the letters didn't really sink in. After reading that educational value wasn't your intention I feel a bit better about this, but I'll still add that I also didn't feel much change in terms of my emotional understanding of Argentinian immigrant life in general, or José Wanza's life in particular. I have a vague understanding that it was bad, that there was abuse of power. I haven't reread the letter outside of the game and maybe only I am to blame for my failure to empathise.