Director Lino Brocka sure knew how to wring a whole lot of intensive, raw emotion out of a relatively straightforward approach to filmmaking, as seen in his little seen (until now with a bluray restoration) very loose adaptation of the eponymous story. What I mean is he doesn't do anything too complicated or outlandish with the camera or the editing, scenes play out mostly in medium shots and with a few carefully chosen close ups (one with the brother Ellis and his Runa late in the fikm is one such example), and he probably aa with his other films like Manilla and Insinang have a large budget.
But I think a more polished look or a studio shoot would take away from the reality presented here, and other reviewers pointed out that it represents a political situation of what it means to live under a manipulative totalitarian; there's narcissism of course as one of Ellis's women points out to her at a key point, but it's also that feeling of 'I know what's best, you listen to me now and do this' and its always to one or the other without consistency.
It's how conflicts and violence escalate when it's among usually reasonable if totally flawed people; Lorens is proud but for all his stern talk a good family man while his brother Ellis is a little spoiled. The mother here, Senora Pina (Mona Lisa, continuing as another matriarchal trauma figure from Insigang), is so striking because she (mostly) keeps an even tone with her sons, and is completely indignant and appaled when others call her out on her BS (and it happens more than once).
Not every performance is always top level (the kids are... kids I guess), but most rise to the demands of Brocka's dramatic demands, but what's so compelling to me is how violence is shown to largely stem from male pride and egotism, and at other times just a sort of blithe ignorance. There's the men on Lorens's side who go on and on about what should be done, and notice how this man is so resigned to what's happening and he can hardly tell them No because, well, how will that make him look? Meanwhile, once things escalate after the deaths of lovers on both sides and Ellis gets some guys who show him how to use a gun, it's like they aren't even fighting for anything (except as one says vaguely "to win") and they're dudes in a rock band(!)
Cain & Abel is another cold, hard, equally melodramatic but harrowingly naturalistic crime drama of how people can be so completely corrupted - most of all by someone close to us (oh, mom). And I can't stress enough how formidable and imposing Mona Lisa is here as this conniving mother of these two grown-ass dopes (or she emphasizes what are their lesser qualities - most of all to the other visa vi their places in the world and with her and in work and family dynamics et al).
