Mario is a simple guy. He wears overalls and a spiffy cap. He’s got a brother and a couple of close friends. He can run fast and jump high. In his various quests to save princess Peach, he makes use of all of these attributes and relationships, yet none of them tell us anything about who Mario really is.
As Super Mario Odyssey has shown us, if you take away the overall, what remains is still Mario, a guy with a fluffy moustache and a pair of delightful nips. What he wears does not define him. Yet most of Mario’s essential properties, the things that make him who he is, are actually purely cosmetic – we would feel weird if Mario shaved off his moustache and spoke to us in a baritone, but we don’t care about the exact nature of his relationship with his brother or if he ever wonders what his life has come to when he has to rescue Peach for the umpteenth time.
With increasing frequency however, games explore the inner turmoil of their protagonists and how their experiences change them. Video game heroes need a reason for doing what they do, and often this leads to them questioning their values and beliefs as well as their relationships with others.