In-universe, Routainen Maa (the Death Song) was written by, and is from the perspective of, the player character's father.
The wooden train in the house is well known, but nowhere is it implied that the player character has a brother. He is, however, confirmed to have an uncle that he has loaned the van from. Thus, it seems reasonable that the song is from his father's perspective, not his.- Unlikely. The family members in the game all have the Kesseli surname, whilst the player can choose their own. This implies they are on your mother's side of the family.
