Somewhat like the Batman comics of the 1970s, it is somewhere between a mix of Adam West campiness (at the end, Batman fights the Joker & henchmen on a giant typewriter) and the grittiness that returned in the 1980s (IIRC, we see both the murders of the Waynes and the Graysons).
Oh, the giant typewriters and other giant props were a staple of the '40s/'50s comics, the Bill Finger/Dick Sprang era. As for the renewed grittiness, that began in 1973 with Denny O'Neill's classic story "The Joker's Five-Way Revenge."
Secondly, the fact that most of the abilities of our heroes were beyond the capabilities of 1970s SFX gurus.
I still dispute that. We're far too quick to dismiss pre-CGI effects technology as worthless, but that's bull. Sure, it may look crude to us looking back on it today, but to audiences at the time it was spectacular and highly effective.
Sure, it's true that in superhero films at the time, there would've been some need to scale back some of the action, but that would've been acceptable. And really, what kinds of abilities, specifically, would create so much of a problem? Let's consider it:
Superman: His powers were quite successfully portrayed onscreen.
Batman: No powers, just fighting prowess and gadgets.
Wonder Woman: A similar suite of powers to Superman, plus an invisible plane. The TV show did an adequate job depicting her abilities, and a movie could've done even better.
The Flash: Superspeed could have been accomplished with animation effects.
Green Lantern: Flight could be accomplished as with Superman; the ring effects would be purely a matter of cel animation combined with on-set wirework and mechanical effects (analogous to how
Who Framed Roger Rabbit? showed cartoons affecting real-world objects).
Spider-Man: His stunts and agility could be replicated in stop-motion animation. The sweeping camera moves through the city could be accomplished with miniatures. (A villain like Doc Ock could've been handled with a mix of practical effects and stop-motion; note that the vast majority of tentacle shots in
Spider-Man 2 were live, on-set effects.)
The Fantastic Four: Okay, Reed's stretching is a problem, but a scaled-back version could have been achieved with prosthetics and stop-motion. Invisibility is an easy effect that's been around in film since the '30s if not earlier. The Thing is simply a matter of prosthetics. The Human Torch would be done with cel animation.
The Hulk: The TV series handled the transformations quite well. On a movie budget, the Hulk could've been shown doing more damage and hurling tanks around courtesy of miniature work.
The X-Men: Cyke's eyebeams are simply an animation effect. Wolverine is just stunts and prosthetic claws, plus a prosthetic mechanical hand for claw-deployment shots and some makeup work for wounds and rapid healing. The Beast is just prosthetics and stunt work; Nightcrawler is that plus jump cuts and a bit of pyrotechnics. Angel could be handled the same way the angel in
Barbarella was. Jean is just an actress pantomiming telekinesis while things are lifted on wires. Iceman could be stop-motion or makeup FX, or maybe just be like Shawn Ashmore in the movies and not transform into ice at all. Colossus is prosthetics and standard strong-man stunt work and wirework. Kitty Pryde is just dissolve and split-screen effects, maybe some rotoscoped mattes; "walking through walls" FX have been around since the '60s.
Dr. Strange: A guy waving his hands and intoning stuff. The supernatural effects around him could be achieved analogously to effects in
Ghostbusters and
Poltergeist.
I don't see anything there that's beyond the capabilities of '70s/'80s FX masters like Dykstra, Trumbull, Winston, Tippett, Edlund, Muren, and the like. Most superpowers aren't that hard to depict onscreen at all, with a few exceptions like stretching or becoming living fire (and to be honest, the CGI fire in the movies' Human Torch isn't that much more convincing than cel-animated fire would've been). No, it wouldn't have looked like modern CG effects, it would've been a bit more scaled back and not quite as convincing, but it would've been just as satisfactory to audiences at the time as the effects in
Star Wars, Indiana Jones, Ghostbusters, RoboCop 2, Roger Rabbit, and other pre-CGI epics. The main impediment is that it would've been more expensive and time-consuming. It wasn't technologically prohibitive, but economically so.
I don't buy the explanation that movie studios were less derivative back then. Look at all the movies in the wake of Star Wars - Flash Gordon, the Black Hole, Star Trek, and, on tv, Buck Rogers and BSG. Even Bond went sci-fi with Moonraker. Smokey and the Bandit spawned the Dukes of Hazzard, Burt Reynolds Hooper, where he played a stuntman, was followed by The Fall Guy. And The Towering Inferno was followed by a host of disaster movies.
On this, we agree completely. I'll never understand why people look at the things Hollywood does and assume there's something recent or unusual about them.