The modern world is incredibly concerned with spoilers: the giving away of surprises before you, yourself, have reached that part in the narrative.
But some of the most effective stories out there are pretty up-front about their most surprising elements and still manage to forge a compelling, interesting narrative. D.O.’s Kana Little Sister is a good example of this — we know from the outset that Kana is likely to die at the end of the game, but that doesn’t stop it from being emotionally engaging throughout, and traumatic when the final moments of the story eventually roll around.
Another particularly effective example of this is in Nitroplus’ Saya no Uta (aka The Song of Saya), a horror-themed visual novel composed by Madoka Magica writer Gen Urobuchi.