In appreciating movies, there are many different elements that contribute to the mise en scene, and they're much more important in some genres than others. Horror movies, in news to nobody, are about scares. Elements like character, plot and cinematography hardly matter, because everything is simply plot mechanics to have the maniac in the ski mask close in on the horny teenagers.

It's the reason the video nasties were so much of their time and place; they could be made cheaply, they were often set in remote locations, and even though such low budgets only allowed for cheap film stocks and dodgy lighting, it didn't take away from the USP of scares and blood (in many cases augmenting it by making everything look even more dark, grimy and putrid).

In some movies it's all about the dialogue and characters, the set dressing, costuming and other visual disciplines barely important except to deliver the script and themes. In many movies today it's about visual thrills and little else. Say what you like about the Marvel universe and the rest of the blockbuster firmament, but it's not exactly about characters who are deeply surprising or who we've never seen before, is it? What else is Tony Stark but Han Solo with all the attendant swagger and quips, after all?

But sometimes, wowing your audience with just one aspect of your moviemaking can backfire. I recently rewatched Avatar and was surprised by how unimpressed I was. It was only my second viewing after the theatrical release, but before it was even over I was pretty sure I'd never watch it again. It was quickly obvious that the technical artistry blindsided us all back in 2009 about how awful the acting was, how drab and pat the characters were and how hackneyed the script was. Like many busters of blocks, it was all about the visuals. In fact it's become something of a cottage industry figuring out why, as the most profitable theatrical movie in history, Avatar hasn't had more cultural impact.

All of which leads me to a conclusion. Plenty of films today make you realise that even though we still equate movies with the cinema, they're not at home on big screens alone. Ask 10 cineliterate friends and at least three of them will foam at the mouth about the sanctity of the theatrical experience, but something the streaming/VOD world has made us realise more than anything else is how much we can enjoy character or plot-driven fare (Primer, Four Weddings and a Funeral and A Separation come to mind, but you'll have your own examples) just as comfortably on a PC screen, tablet or phone.

Even if you watch a badly coloured or out of focus movie from a torrent file (so a friend tells me), sometimes the visual quality just isn't a lynchpin of enjoying the experience. Of course the director would be having a fit to know you're consuming his/her film with image fidelity they'd never want it shown in, but if the movie's actually about the story or script, the visuals can be quite plain, even boring, and still tell the tale satisfactorily.

Which leads me to the ultimate point I'm trying to make. What makes a movie? What keeps us interested in a movie?

Ask any screenwriter or director what really matters to the audience and they'll toe a very entrenched party line in the film industry when they say it's the characters that make us care. Now, you might be wondering why I sounded so cynical about that. The reason is because for the longest time I didn't believe it and in many ways I still don't, simply because of the number of bland rehashes of characters I've seen a million times in movies where it's obvious they only cared about the thrills, CGI or action (we're looking at you, George Lucas).

Because we rarely see characters in films, we see one-note archetypes (Han Solo/Tony Stark/Peter Quill/etc). And they're often so cursory and so entrenched according to Hollywood narrative conventions you can tell not only what kind of person a character is but the situation they're going to end up in as soon as the actor opens his/her mouth. And I'm not talking about the other old chestnuts like 'antihero' or 'shades of grey' either, I'm simply talking about characters who are like real people and all their good and evil, foibles and failures in one fathom-long body.

A perfect recent example of how the characters mattered not a jot was the umpteenth reboot of Robin Hood, made for the videogame generation and starring Taron Edgerton as the titular Middle Ages-era English robber. While director Otto Bathurst wrangled some very well choreographed and staged fight and training sequences, the characters were barely sketches. Maid Marian was every inch the winsome, disposable love interest heroine with a few concessions to modern feminism thrown in.

The actress playing her, Eve Hewson, didn't even bother to maintain her accent from one scene to the next, wobbling somewhere between stand-up act Irish brogue and Iowa farm girl. Care about the characters? Only because her ample bosom was constantly heaving out of her clothes, and the less said about Egerton's completely hatstand portrayal of Loxley the better.

But I found myself schooled recently in how characters actually do make a movie sometimes, and I came away glad I finally had a handle on why rather than just repeating the conventional wisdom about it when 80 percent of movies told me otherwise. I watched two movies back to back on a plane flight recently, and one had me on the edge of my seat and the other put me to sleep more than once. Out of the character drama and the violent action movie, guess which was which.

Blade of the Immortal might have had a little bit more impact if it had been a physically bigger image, but not much. Takashi Miike's bloody supernatural samurai fable had plenty of sword fights and went through more than a few buckets of fake blood, but I found myself drifting off a few times. It wasn't just the fact that it was all subtitled, being as it was in Miike's native Japanese (a practice that often renders dialogue very simplistic, excising any native nuance that might make it more lively). Lead character Manji had so few dimensions he was no more than a cypher, the strong silent warrior driven by vengeance.

Was that a problem? Absolutely not - plenty of movies have been more creatively successful on far less. Just look at Star Wars, where you can sum up the lead trio in seven words (idealistic farm boy, cocky pilot, feisty princess). But 140 minutes of it kind of dragged, feeling much longer as I waited for the plot to deliver me to the next action scene (now there's a familiar Hollywood methodology).

Next up was Molly's Game, which had the exact same running time but which raced by all too quickly. The first element that had me rivetted was the character of Molly, played by someone who's as talented as she is pleasurable to look at in Jessica Chastain. A former competitive ski jumper who ends up hosting a high stakes poker game for rich elites, Molly was quite simply an interesting character, someone I'd never seen before (Chastain did the same thing with her last movie Miss Sloane, which bought a real person to life more thrillingly than a hundred planets exploding, buildings collapsing or intergalactic infinity wars).

And then in a perfect storm of writing and casting, Chastain and her costars bought writer/director Aaron Sorkin's crackling dialogue to life with an energy all its own. Like we all felt the first time we watched the three-hour-plus Titanic, it could have been twice as long and only my bladder would have realised.

Here in front of me was the proof I'd always been seeking that characters matter, and since then I've been watching for it everywhere. Just like those pictures hidden in the swirly patterns that were so fashionable in the mid 90s, it's easy to spot when you know what you're looking for.

Aquaman was good fun, but the characters were as thin and archetypal as they are in any superhero movie. Mera (Amber Heard) was the seventy-thousandty-eleventieth Princess Leia retread, a gutsy, capable woman who has to roll her eyes while she leads the lunk-headed hero to his destiny. And Arthur Curry/Aquaman (Jason Momoa) was the lunk-head, all hard-living, quips, Dwayne Johnson-tats and cheeky smile. Like in most movies of its ilk, you have to enable a filter to ignore how thinly devised the characters are so the thrills, action and visuals can keep you entertained without too much overt disappointment in the experience.

Going into Deepwater Horizon I expected the same thing Peter Berg (and his spiritual blood brother Michael Bay) specialise in; no-nonsense, tough talking first responder-types who kick bottoms before taking names. But even though the characters had a lot of that I was pleasantly surprised by the degree to which the script (as well as Berg's direction) went further to make them seem so realistic according to what appeared to be the real people involved in the incident.

An unexpected example came from cheesy 1980s sci-fi thriller Night of the Comet. Where the rest of the cast could barely act wet if you pushed them into a bathtub delivering such an irascible script, I believed wholeheartedly in the character of Regina because Catherine Mary Stewart was such a natural, even in such a dumb and forgettable movie.

But here's something else about character. A character who's interesting in his/herself is so rare, seeing one on film is like winning the lottery. Most characters are defined in response to another character. In the case of Molly's Game, Molly's lawyer Charlie was an interesting guy too, and portrayed by a great actor in Idris Elba. But Molly was great on her own.

Think again of Titanic. Anybody who saw What's Eating Gilbert Grape or The Basketball Diaries already knew what a great actor Leo DiCaprio was, likewise Kate Winslet in Heavenly Creatures. But in themselves, the characters of Rose and Jack were complete archetypes as the stifled rich girl and the free-spirited pauper, neither actor having to work very hard.

It was only the way their lives collided that generated the romantic sparks and made a generation of teenage girls love the movie just as much as Academy voters did. Take either of those elements away and the other would have been like one arm of a nutcracker - as colourless as it is useless.

Am I reading too much into it, or are truly great characters the single reliable element that will keep an audience hooked? And is creating or portraying one as difficult as it seems, because we see them so rarely?

Not a real lot has grabbed me on screens recently. As an Alex Garland fan I was looking forward to Annihilation, and while it's his least accessible story it's got some great ideas and images in it. I was also pleasantly surprised by a teenage romance drama called Every Day. Not only was it serious, well acted, well told and didn't get bogged down in a somewhat silly concept, it's very hard (as a man in my late 40s) for any movie to make me the slightest bit interested in teenagers and their problems.

But the most pleasant surprise I had recently was 1991's Sleeping With the Enemy, which is in the midst of getting a remake. I know I've come to it late but I never saw the Julia Roberts spousal abuse drama when it was in cinemas. If you've never seen it (or haven't in a long time), it'll remind you why Roberts became such a big star so quickly.