I see people saying you need to know about the Colombian context in order to truly understand this film. Maybe that is true to an extent, but the director deliberately removes any context that would tell you about the situation. That is for a reason. Because context is removed, you don't know who the characters are fighting for or why they're fighting. You can't say whether they are on the 'good' or 'evil' side, if there even is one at all.
From the get-go the film immerses you into their lives forcefully and vividly. You don't need to know what the wider context or motive is to understand the very human drama. What I see is children making decisions based on a range of factors: fear, power, pride. But I also see children who are missing vital components of a human's existence because of the war that forces them to think like robots at times. Paradoxically, they also have the freedom and lack of authority to let them run riot at times, manifesting in wild, irrational decisions and bizarre, disturbing rituals. This unnatural state of being, war plus lack of social structure, is the cause. Yet you do get glimpses of their youth being expressed in more innocent ways, that remind you that there is still some humanity buried in there.
I like that despite the situations the characters are in, Monos isn't bothered with making you pity them. It's interested in things other than that well-worn trope. It doesn't try to make you hate them either. Rather, it shows how they can do evil things, irrational things, and occasionally, good things. But ultimately, child or adult, war makes demons of us all.
Another thing that really hooked me into this film is the cinematography, which is at times beautiful but is foremost fixed on expressing the characters' emotions. During crazy ritualistic behaviour, it becomes frenzied. As the group becomes increasingly disjointed, the camera is increasingly disorienting too.
