Get Out of My Way, Devilish Duke!

When someone needs an enormous amount of money, what can they do to get it? Sell a kidney? (Yeah, that's an appropriate option) However, I became a game tester. All I have to do is to make sure that the MC and ML will reach their happy ending. Sweet! Easy Money! What if the game was harder than I thought? And what's this hidden task?! Do I really have to reach my own happy ending too?!