To make something from a Marvel concept this blithely, wonderfully and resolutely weird demands time and budget and maybe most of all commitment, and none of those three things showed up to set. There's no scale, here: Everything's hedged, hemmed-in, cramped. The script feels like a first, place-holdery pass. The sets and costumes (and in the case of Medusa, the wigs) seem rushed, flat, devoid of texture.
That's not about the design, but the execution what should be one character's quarters in Attilan's huge cosmic space palace, for example, looks more like a Boca timeshare. You keep looking for the wicker dolphin.
And the acting? Hoo boy.
The main characters are fine. Swan improves immeasurably once she's allowed to get her knuckles dirty; as the forbidden-to-speak Black Bolt, Mount scowls and scowls and scowls, but once on Earth he gets to throw in the occasional affronted eyebrow-pop. It may not sound like much, but compared to the show's alarmingly wooden bit players, dude is liquid mercury.
(As the show's many ancillary characters deliver their lines, you'll wonder just what exactly they're doing, and why. And which producer they're related to.)
The slapdash approach evident in every aspect of production ends up mattering hugely, leaching color and life out of even the moments that work, and poisoning the ones that don't. There's a flashback involving the discovery of young Black Bolt's powers, for example, that's shocking in theory, but hilarious in execution. It's meant to strike a tragic note, but the result is emotionally closer to "Yakety Sax."