I saw this on YouTube back in 2019, mad lad's uncensored video was remove 1 year later. The game he played was a hentai game where you play as the antagonist, the Demon lord. Then there would be the female protagonist that would try to kill you, there it would be like a VN game with small minigames. There are several endings, the ones I remember is when the protagonist gets brainwashed and is used by the demon lord (the player) for their personal use, and the other ending I remember is when the protagonist looses the battle and is humiliated as she becomes the demon lord's sex slave.