American McGee's Grimm: The Singing Bone

In The Singing Bone, the second season's second episode of the American McGee's Grimm series, two brothers seek to slay a wild boar for the king who will bestow his daughter's hand in marriage to whomever does so. When the younger brother manages to kill the boar, he passes by his older brother who's been loafing in a tavern who then kills his younger brother to take the credit. Having hidden his body, years later a shepherd hears the bones singing their tale of woe and takes them to the king who finds out the truth and has the older brother killed for his crime.

That's actually the "light version" of the tale which Grimm goes around changing through 6 levels into a much darker version by touching as much of the environment as possible to increase a dark meter enough to move on to the next level. Story elements change as the darkness increases, including Grimm riding the boar who lays down a swath of death and gore through villagers and livestock. The final dark version of the story is shown at the end of the completed levels.