What is the point of the game?

[Milkway"]

that is the most stylish and curious 2D hgame I have ever seen outside visual novels.
So, this is more like a nukige or something with h fanservice or the game has darker themes and narrative questions around it's plot and h elements? I would kinda enjoy if it was the second case

[Harpo Mungis]

It's a raising game. To put it into the most understandable terms I can, it's similar to Persona, I guess. You have a certain amount of time in the day to spend raising your stats, earning money, interacting with your sister, etc. You'll get deadlines where you'll have to win certain battles or trigger specific interactions which will net you a game over if you fail. Getting a game over will force you to restart, but you'll get points to carry over some of your progress.

The plot and all of the H content is extremely vanilla. Early interactions are non-consensual by their nature, but you're never allowed to outright force yourself on your sister, and it quickly blossoms into an adorable, loving relationship. I haven't finished the story yet, but the darkest it ever got was "there's super strong monsters coming!"