Well, ok, some analysis.
I like the basic setup of the story, and how it's different from the main series. But I have lots of problems with the story, mainly that the PC is given a hugely important title with almost religious reverence, out of pure nepotism from no actual results. And there's no reason the title or role should even exist, or given to just one person. And next to no one even comments on the ridiculousness of it.
The other maim bugbear I have is that they took a 600 year trip to another galaxy, and no one apparently considered anything might go wrong, and apparently everyone expected it to be paradise on arrival. This kind of plot might suit a wackier setting with inefficient government like Outer Worlds, but doesn't really fit ME.
There's a lack of suspense because the enemies apparently have a big space fleet, but prefer to have small squad shootouts on planets.
None of the characters seem that interesting. Dunno how the plot develops, maybe it'll get better.
As for gameplay, it's a weird mixup of ME1 and ME2/3, with wide open areas but still cover-based shooting. It kinda works ok, and is not that bad really. But most of the gameplay time is taken by planetary or area exploration, which just mounts to go to place X, press button, listen to narrative. Which would be kinda ok if all the places weren't so huge or if the narrative was interesting, so it ends up just being boring.
Also, the game feels a bit unpolished. Lots of weird stuff, like stuff floating in the air, monsters spawning at your feet, the save corruptions I mentioned, which all just smells like unpolished content.
I didn't follow ME:A when it was released, but I assume it was the lack of polish and uninteresting characters that killed the interest in it.