We don't get enough games that could be considered up to interpretation, the themes, the story, the characters, too many tend to simplify things even in the best of games. Yet Shadow of the Colossus, one of the simplest games in terms of plot is one of the most complex and artistic videogames that I have ever played.
One of the elements that could be broken down is the role that Wander plays. The first time I started to piece this together is the role the Colossi play in the game, people would argue that they're not villains, they're creatures that just walk around and some won't attack you until you attack them. Even when they're beaten, the player doesn't get the sense of victory, the game becomes rather sombre and tragic, making you question whether they are actual monsters. We see the game from Wander's perspective, we want to save Mono, the Colossi are our targets, they look like monsters so we assume they must be evil, because narrative dictates that's how it is.
But what do we really know about Wander?
We know that he stole the sword he fights with, he's trespassing in a forbidden area, made a deal with a demon, killed 16 creatures to bring back the life of a woman who was sacrificed for the supposed greater good. The details of some of these points are quite vague, we don't know why Mono was sacrificed specifically, for all we know it was completely voluntarily, we don't even know the relationship between Wander and Mono, she might not even know him and he is doing this for purely selfish reasons. But that's just speculation, again, looking at the facts, Wander performs multiple crimes with no justification or context given. If the game makes us sympathise with the Colossi and chooses to keep the facts of Wander hidden, only revealing the negative actions he's committed, you have to ask yourself, were we playing as the villain?
So who is the hero? Is it the Colossi? Well no, i wouldn't say they play a role of hero or villain, just victims of circumstance. Is it Mono? No, we know literally nothing about her. The priest and soldiers? Most likely seeing as they fight against the demon, Dormin, they're also the ones that inform us of Wander's crimes, but again, not enough context is given for us to make a decision. The only character in the game who comes close to being a good character is Agro the horse, she's brave, protecting her master and even sacrifices herself to keep him alive. But apart from that, there is no clear hero in this game, and if we're to go by facts alone, Wander shares a lot more traits and plot points to a villain than he does a hero.