The Kittens Game, located at http://bloodrizer.ru/games/kittens/# subtitled "A Dark Souls of Incremental Gaming", is a village-based idle clicker where the player must manage a village of kittens. The game is text based, using html5 to portray its increasingly complex world.
The player begins by gathering and crafting a small amount of resources, which they then use to get other resources, build structures, and research technologies. There are no enemies or opponents, the only enemy is a lack of food, and the game can be left by itself to slowly gather resources over hours or even days. An active player can click and build quickly, but an unattended game will also slowly improve. Sounds like a fun thing to tab to in your browser while doing serious work?
The game uses the tag "dark souls" because it gets very, very difficult. Users can build more structures, but each structure costs incrementally more, with the costs growing exponentially. The first hut costs 5 wood, the tenth might cost 10,000. The marginal utility of everything grows rapidly, hitting a resource cap which can be negotiated around only by building other structures that cost even more. At first, the player has a burst of euphoria while they build carelessly, followed by needing hours and days to slowly gather enough resources to build, say, one additional library. At a certain point, a player can reset, starting the game over again with a small bonus to production. Then, getting a little bit further, they can reset again, slowly building up their resources. A player can never truly "complete" the game, just continue to play and get slightly more resources. Imagine a game in the Civilization series, if it was based on text, and took an entire weekend of hitting buttons to get a single technological advance.
I originally intended to write about this game last year, after playing it for two weeks. A year later, with some breaks, I am still playing, enjoying seeing my total score (measured in "paragon") slowly inch upwards. I also enjoy the fact that the game is still under development and that new challenges and resources come out every few weeks.
While it might not sound exciting, this might be the game you were looking for, even if you never knew it.