Aquaman could have used more octopus percussionists. This bloated, big-screen take on the DC comic is dumb, but not nearly dumb enough. In the title role, Jason Momoa seems game, entering the movie as he does with a wet hair flip and a growl. But unlike Chris Hemsorth—whose Thor is the Marvel corollary—he doesn’t have witty material to back him up. Instead, Aquaman drops hard-rock guitar riffs on the soundtrack to bolster the groaning one-liners, while otherwise giving over too much of the running time to banal undersea politicking. (There are a lot of conversations between various water kings, princes, and princesses, all of whom amusingly use their hands to paddle in place while bickering.) The water setting also makes this one of the fakest superhero movies in recent years, as reliant as it is on weightless and spaceless CGI. Meanwhile, director James Wan prefers a heavily digitized 360-degree camera motion in the fight sequences that makes it seems as if we’ve suddenly fallen into a video-game cutscene. There is one striking image, as Aquaman and Mera (Amber Heard) swim down into the watery deep with a flare lighting the way, hundreds of skeleton-like sea creatures in pursuit; it’s as if Hieronymus Bosch had dedicated an entire painting to Atlantis. Otherwise, Aquaman should have stayed away from fine art and instead embraced its calling as camp. This is a movie that features Willem Dafoe riding a great white shark underwater, and it can’t decide if the image is cool or silly. (Hint: it’s silly, so go with it.)