People view this story too literally- a theory of mine:

[redsky1335]

I think a lot of people took a much too literal approach to the story of this game. First, what do we KNOW for sure that it's about? Grief, and the inability to handle the loss of loved ones.
Hear me out: I THINK THE ENTIRE GAME WAS IN THE YOUNGER BROTHER'S HEAD, except for the overaching major events (the death of the mother, father getting sick from grief, death of brother)... So the game starts with the loss of the mother, father in a miserable state. The brothers are there for each other, living through the struggles of day to day life relying on each other. Each obstacle can be looked at as some kind of social situation or problem where the brothers help each other.
But as the older brother gets older, he suddenly becomes less interested in hanging out with his little bro... and more interested in chasing skirts. This makes a younger brother feel immense betrayal. The symbolism of the spider-woman luring his big brother away with her feminine charms is pretty obvious; I won't get too graphic, but "entering a mysterious hole that the little brother doesn't understand"... the little guy is afraid that he's going to lose his brother to the woman. And maybe he does- maybe a year or two passes, and older bro is a man, marries the woman and moves away from home to start his own life? That'd leave the younger bro thinking that his wife is some kind of... MONSTER who stole his brother.
After this, maybe his brother did indeed get killed, sickness or joining the army. It took his brother dying for the young one to move on from the death of his mother and stop blaming himself.
Why do I think this? This game is a very cinematic experience- one of the biggest people involved is a film director (you can really tell) known for use of symbolism and leaving things unsaid for you to fill in the blanks. Works perfectly here- you can look at the whole thing as a literal adventure, where the boys have to cure a physical illness of their father and travel to all these amazing places, or as more vague "This is how the little brother sees things through the eyes of a child with very little understanding of the world and reality and maturity."

[A2k]

Nice

[redsky1335]

I just thought up something the "War of the Giants" could mean: it could represent an actual war between humans as seen through the eyes of children. The scale of something like a battle would seem ENORMOUS to young people- the size of the bodies is trying to depict that war is something so big, so horrible, and that it's often leaving terrible obstacles for the younger generations to navigate.
Also, on the burial: just as younger bro leaves big bro, he climbs a "growth" (the magic tree) and as he climbs it, the DISTANCE between the brothers is shown visually growing; as you get further up the tree, you can see blue bro sitting alone at the base. GROWTH SEPERATES THE BROTHERS before they are seperated by death.

[Tilen]

It goes all the way up to the White House.

[redsky1335]

Originally posted by Pope Francis:

But thats just a game theory

Of course it is. I can suspend my disbelief and take it all literally, but if a game can make you think like this it's doing something right. Just fun to theorize about symbolism in a game that's ambiguous with imagery and dialogue.

Or was that comment just a punchline relating to that YouTube channel? :P

[Doc Holiday]

The spiderwoman is definitely a metaphor for how women can ruin our lives. And you observed pretty well on the "hole" aspect, well spotted.

As to your theory of "everything is in the character's head" (that's a theory everyone loves to apply to everything), no I don't agree.
That makes the gameplay bit near the ending less powerful than it is: with the loss of big brother, lil brother finds the strenght to do it all by himself. This is a story about growing up.