Solarium, by Alan DeNiro, is a web-only game. (Technically you can download it, but since it's an HTML file I'm not sure there's a point to doing so - you'll still be playing it in a browser.) You can play it
here.
In the notes I kept as I played this game, I wrote: "This reminds me of Margaret Atwood." Then, a few minutes later, I added: "This reminds me of
Bob Dylan's 'Isis'." Finally, I wrote: "This reminds me of nothing I've read before."
This is not a classic text-adventure-style IF. It is not really a game, but a beautiful work of fiction. The reader is allowed to explore the story in various orders, though the experience is controlled enough for the story to flow. Sometimes non-parser-based games make me feel too constrained, like old-school Choose Your Own Adventure books, but this one still gave me a feeling of agency.
It didn't hurt that the writing was, frankly, fantastic. I think this is one I'll come back to.
I know I've said very little about the actual game, but... I really think this is one to experience.