Achievements? Do you mean the gallery?
Yes, the gallery seems to be somewhat bugged, partially outdated with thumbnails made from old renders that do not exist in the final version. It also seems to have some wrong hints for unlocking some of the items and some of them get unlocked without actually playing the path they're from or seeing them in game, because they have wrong variables unlocking them (same variables duplicated from previous items).
Also, all the replay items are based on duplicated code, copied from the main game script, creating lots of extra work for every change in the main script to update the replay gallery. I'm not even sure that the scenes in replay match with the original 100%.
So yes, the gallery seems to be kind of half-assed. It would have probably taken a couple or more weeks to fix.
(considering Oceans coding experience, a more experienced programmer could probably do it in a couple of days)
I never even paid any attention to it until someone asked about the gallery in this thread. Then I checked it out and found the problems listed above. I'm guessing that Oceans focused on finally releasing the game with the working main game in mind and just ignored the gallery part, just as he did with the phone feature and the whole Nami's photobook part of the gallery.
Personally, I don't care if the gallery exists or not. I'd rather he focused on the story. Although, Nami's photobook could be interesting when it finally gets released, since it's supposed to be made by Nami, based on what Nami has seen.
My suggestion:
Just play the game and forget about the gallery. If you want the gallery to work to look at all the pretty pictures, just unren the game.
Nah, all Oceans characters are flawed, Bella being one of the most messed up ones. This is what makes this story interesting and we just like the characters regardless of their flaws.
But if you mean that Bella is so perfect that even her flaws are perfection, then this is just what a Bella simp would do. I should know, I'm simping several characters of this game the same way. 
