There is clearly an audience for Ling: A Road Alone. It's the kind of gamer who does Final Fantasy runs with level one characters, or who plays Dark Souls with a Dance Dance Revolution gamepad. That is to say, Ling: A Road Alone is absurdly difficult for the sake of being absurdly difficult. If that's your kind of thing, the kind that is often unfair or sadistic in its difficulty, then Ling: A Road Alone is a must play. Otherwise, there's not much here that can be recommended.
Not all games that focus on a few, selected mechanics are bad, of course, but any game that narrows its focus to such a small set of moves had better make sure those are brilliant or that there are other, supporting pleasures, like an interesting narrative to fill out the experience. The developers seem to think that minimalist presentation, limited mechanics and high, often unfair difficulty and repetitive combat are enough to distinguish Ling: A Road Alone from other hack-and-slash games. Come to think of it, they’re right.