Simply put, Mashle isn't supposed to blow your mind or do anything extraordinary. It exists to speedrun standard shonen tropes in a funny parody setting. For anyone looking for deep stories and worldbuilding... this ain't it. But as far as just pure fun and shenanigans go, this is as good as it gets. It doesn't waste your time or blow its own horn, stuff just happens and the further it gets the more absurd and funny it becomes. It's in no way the best anime out there, but it manages to combine the absurdity of One Punch Man and the generic character of every shonen everand make it work to its benefit.