before i get started, i would like to mention that i actually give this anime a 10/10, but this is for personal bias, but within subject of fairness of an analytical review, i stated the OVERALL is 9.5/10.
the only reason i didn't give this a 10/10 rating is because of questionable plot devices and vague plot element explanations through out the entire series (which includes the original "prequel" of Clannad), and on that note, i hate how people separate these two as different series in the same franchise, since you know, the story is consecuatively the same, they are basically just a first and second season of the same story, so i suspect KyoAni just boxed them differently for budgeting reasons and the gimmick that in the game you have to play through the different plot arcs to unlock the endgame "After Story", thus, this second season was called After Story.
aside from the unanswered questions left by the plot devices and elements, the story is very meaningful and deep in more ways than one, and isn't merely a plain romance, but also a story about love for family, friends, and town. if you prefer realism, this isn't an anime for you, it is romantically inclined since the first season, and so there are parts where it's more about the symbolism than rather "can this happen is real life?". so if things like this doesn't break your enjoyment of the series by itself, then overall this is something worth watching all the way through.
Kyoto Animation are amazing, and though they don't do super wild animation, this story doesn't need anything like that, so it was perfect for what they needed to accomplish.
SOUND: 9/10 (MUSIC 10/10, ENGLISH VOICE 8.5/10, JAPANESE VOICE 9.5/10)
first off, i haven't watched a lot of the anime in japanese voice, but i had been told that the voice actors from the anime were the same as the Visual Novel, and i've been playing a lot of that and have been mostly satisfied with such. as for the english voice acting, i am just not happy with Kyou Fujibayashi's voice, even though it sort of fits her personality, it is drastically different from the original VA's japanese voice. i could say the same for Youhei Sunohara, his japanese VA was better for the role, as much as i like Greg Ayres, i felt like it didn't fit quite as well. other than that, i have no other real complaints about the english VAs.
the music in this anime is amazing, from the opening, to the ending, to the ambient and filler musics, most of all were directly from the Visual Novel, composed by wonderful artists such as the former head scenario writer of Key/Visual Arts, Jun Maeda-sama (i'm a fanboy) who handled about 30% of the soundtrack of Clannad, but there was also Shinji Orito who i also have great admiration for also, did about 40% of the soundtrack, and last but not least, Magome Togoshi who also did some beautiful tracks as well. as a personal opinion, the music in this anime is half of what i loved about it so much, it sets the mood almost perfectly in every scene.
okay, i know this seems like a low score, but if you know me, i don't deem something "bad" unless it's below 5/10. the reason i am giving the characters a lower rating than everything else, is that you eventually realize that this story isn't as much about the characters having a journey, as the story using the characters as conveyance of the plot and meaning. that probably didn't make sense, but i can't elaborate without spoiling, i'm sorry.
to simplify what i'm trying to say, i think a lot of the characters are just there to fulfill a trope, while being an element relevant to the story's purpose, like, i guess as a small spoiler (if you didn't see the first season), look at Nagisa Furukawa, she loves the Dango Daikazoku, because they are a big happy family, what a coincidence, Key advertises this anime as about "love of family and town".
i kind of wish the characters were a little more deep, and i realize that in the anime this doesn't matter as much because the supporting cast are not as relevant later on in After Story, but i personally just feel like this ground is a bit shakey even with Tomoya and Nagisa, and i can't explain why without spoiling, and so maybe you'll notice it all for yourself, maybe it's too subtle or you won't be distracted with character traits and this won't be an issue for you like it is for me.
all that really matters though is that even though i was not extremely happy with the characters, they were good enough to be entertaining and hold enough interest and meaning to the overall story that it made this one of my favorite animes.