Animation Quality: 10
I think this needs no explaining... It's KyoAni after all
Characters: 9
Although they fall into your typical category (Sickly girl, cousin, tsundere, loli etc), Kanon managed to mould their characters very well, making them very different from other typical harem characters. Instead of the typical cousin-who-has-a-crush-on-main-character build, Kanon managed to make Nayuki interesting by adding in her oversleeping problems. Although they may seem very steoreotypical from the start, once Kanon begins to develope them, they start to shine. Definitely a plus point IMO. The only complaint I have is that some characters seem to be forgotten once their respective arcs are over (like Amano for instance), but seeing that this is a VN adaptation after all, I don't think KyoAni could have done much about it either.
Voice Actors: 10
I liked how KyoAni scripted Tomokazu Sugita as Yuuichi's VA, especially his sarcastic remarks that reminded me of Kyon. I also liked Ayu's "Uguu~" (Yui Horie!!), Nayuki's slower-than-usual responses, and Kitagawa ;P I think there's no reason to give it any less than a 10.
Script: 8
I liked Shiori's arc the best, but the others weren't too bad either. Mai's arc managed to be semi-tragic yet exciting at the same time (Shinjin... Sorry, demonic battles, anyone?), while Makoto's arc was just plain tragic. That said, I feel that Nayuki didn't get enough attention (not that I'm blaming KyoAni or anything, since Kanon is a VN adaptation after all), and I just plain disliked the ending (It sorta diluted Shiori's arc for me). IMO they would have been better off ending at 23, but maybe that's just me
Adaptation from Game: N/A
I haven't played the game before, so I don't think it's fair for me to give it a score, but based on what people have said around here, it seems that it was managed very well, especially the last episode. I'll just refrain from giving this a score
Music: 9
I really, REALLY liked the way they played Canon in D three times throughout the show. If you noticed, they played the song during episodes 1, 13 and 24, which are the beginning, midpoint and ending respectively. Coincidence? I think not ;P One more thing about the music is, having played EFZ, I recognized some of them (i/e: Character Select Screen) even without playing the Kanon game or watched the Toei version, which was definitely a plus for me.
Bonus:
AIR references (Peach-train, book store, rice shop etc.) +1
Final Rating: 8/10
Kanon was one of those shows which started off as a very typical drama/harem show, but quickly grew beyond that. It managed a skillful blend of drama, comedy (that dance scene was brilliant
) and tragedy. Although some supporting characters seem to be forgotten once their arcs were over, Kyoani managed to remind us of the other main characters from time to time (Makoto's bells in Yuuichi's drawer, Yuuichi's reference about Mai and Snow bunnies when Nayuki asked him about them etc.), and that's something I greatly appreciate. Although I still can't really get over the ending (Would have been a 9/10 if it ended at 23), I'll admit that Kanon was one great anime, and as such rightfully deserves an 8/10.