Just finished binging the second half of Fate Apocrypha because I quit in the middle and always wondered how bad it could have been?
Quite bad. Fate Apocrypha feels like a soulless mishmash of ideas from the Fate series being used by a shitty writer, ie. a fanfic. There is a big problem of characters reacting like retards for no real reason and forgetting basic shit they can do because that would break the plot. For example, Assassin attacking a character that doesn't use her command spells to recall her servant, despite that being the very point of command spells. Or the very act of that assassin attacking its own team being purely due to the writer not having anything to do with the character besides filler. The whole system of servants doesn't seem to matter anymore. Assassin is just a caster (who's completely identical to Caster from the original Fate), Rider not being able to outrun anyone despite it being his fucking point. Everyone are just as strong as the plot needs them to be rather than have distinct pros and cons.
But the biggest problem in the show is the focus on servant characters. A big point in the Fate series is that, barring Arthuria, the servants summoned are basically copies of the original heroes. Meaning any event they went through is wiped away from their souls after being released. This makes any character developement of theirs completely pointless and the show seemingly forgets that incredibly important factoid, since it literally dumps almost all the masters midway through. The characters that are not servants include the extremely boring main character Sieg, a homonoculous who needs to face the fact that human societies will always fuck over part of its populace. Oh it's so deep and complex! Should we like human despite them killing each other? Someone inform Hajime Isayama of this deep masterpiece.
The only good thing about the series is Mordred and her master, who are pretty much the only interesting and likable characters. Also Siegfried is a failure and from what I heard it seems to pass over to the Gacha. And loli Assassin should have killed Jeanne because, at least if I remember correctly, in-lore, the more specified a curse it, the more powerful it is. And loli Assassin has a fucking checklist of requirements. Also shouldn't the ability to summon "evil" servants be due to the grail being polluted?