I really like this game, even I don't know if I can call it a 'game'. ಠ_๏
Actually you hire 'workers' and they produce Gold and Mana in a certain time.
Then you can summon the monster girls.
At the beginning, you will get the first 3 relatively fast but then... it goes up to more days than i imagined.
You could buy crystals to speed up the days. Luckily, you don't have to be in the game to produce more Gold or Mana. So, if you want a game where you are waiting several days to get your monster girls, it's perfect for you.
Also mentioning, it's worth downloading the R-18 patch ( ͡° ͜ʖ ͡°)