I know this game may be dead now... But... Oberon.
Fate/Grand Husbando (Preview version)
A downloadable game for Windows and macOS
A doujin game based off of the Fate universe, specifically Fate/Grand Order. This has been in development since last year at r/GrandOrder and it's finally gotten to a point where the prologue can be played through. There's working affection, choices, a CG gallery and nine endings.
But don't expect too much, because this is literally just a preview/teaser for the game. It contains the prologue/set up and early art. Some of the sprites (such as Mashu) are outright prototypes stuck in there so she isn't a blank space. Most of the audio and visual assets are likewise there so that it's not simply silent and empty. (which doesn't mean some aren't a little bit fun...)
There are a few other working systems in the game, but they have no effect right now, such as the angel and devil system (a prototype term for now) that will determine the MC's personality and as the game progresses lock in choices/open up new ones dependent on previous personality trends.
Development is super early, so input, hopes, expectations, and even characterization concerns are all important and solicited.
If you're a fellow developer or artist also interested in helping to create the game, that's welcome too.
Disclaimer: This is a fangame, and therefore I don't claim ownership of Fate or the characters within the game.