Story
If there's one thing that truly amazes me about this show, it's how many people complain about it being "cliche". A good story isn't necessarily an original one anyway, an extremely well written variation of another story can be a great story.
Well here's my argument about GC's story.
Guilty Crown's story is original, no matter what people say. However, it mixes in common cliche events from other stories in certain parts of its story... which is also why many argue it's a cliche story. As an example, there's an area in this show where they use the common "transfer student" technique... but unlike in many other shows where it's a huge changing factor in their life, there's an actual purpose unrelated to bringing about a random change that everyone can see coming.
On the other hand, it's also true that there are other ideas they could've used, but it wasn't something that ruined the plot.
Unfortunately, this show's plot starts going downhill from about 2/3 into the show.
The whole story actually follows its own logic for the majority of the show, however once it hits this 2/3 point, it suddenly begins ruining everything it built up.
The story seems rushed, and the producers tried to twist the story, however they really didn't do a well in doing so. With sudden rushing and a change in mood, what could have been a slower, well developed story finished as a sprint with nonsensical plot changes and unexplained story developments. The story even failed to follow a decent logic, which it had done until that point. Finally, the ending of the show was extremely unsatisfying, and they did something they shouldn't have done there.
Or, to put everything I've said in shorter terms, the story started out strong as an 8.5/10 with the potential to get an even better rating if they continued the same way, however the sudden change really made the story go down the drain. Everything was wasted.
Art
Guilty Crown stands out in the art criteria, and probably always will.
With magnificent and fluent animation, pretty drawings that I could only dream of doing and backgrounds that draw out the correct moods, it would be an understatement to say the art is great.
Sound
GC has some amazing soundtracks, many of which I frequently listen to. With soundtracks like Bios, Friends, Release My Soul and such, it's no wonder this show is praised more for its music than its own story. Not only does the nice music help with the mood and keep the show entertaining, it gives something nice to listen to after the show. The voice acting is very well done, and this show really deserves all the praise it gets for the sound section. If you're not going to watch this show with any expectations for the story, then watch it for the amazing soundtracks.
Character
The characters in this show are more cliche than anything in the story itself. Many of the characters are truly boring characters. The protagonist is well done, he undergoes many drastic changes that help develop his personality. The main heroine is also well done, and the best character in the show. As a more original type of character you don't see too often, she appeals to the viewers as cute and she does what she needs to do. As for the supporting characters, they're annoying as hell. Overly used personalities and boring stories to go with these characters, there's nothing to be impressed with.
Enjoyment
Anime shows in general- and particularly action anime shows- are meant to entertain viewers, yet it feels as though the producers of this show were purposefully trying to annoy their viewers in certain parts of the story. Particularly where the show went rough, 2/3 into the show. Although it's true shows aren't always trying to entertain you, as they try to make you feel in a way that makes the show seem nice, for example in horror shows they want you to feel frightened and in drama romance shows, they may want you to feel sad, trying to piss the viewer off really isn't a good thing to do. The nice animations and great soundtracks make for an enjoyable experience for the most part, however the characters really do help ruin the experience, furthermore as I mentioned, the story drags the enjoyment down near the last bit of the show.
Overall
A decent show that's special but plain at the same time, it's a very pretty anime show, however candy coating it doesn't necessarily make it sweet. A failure in a proper plot change 2/3 through this show really bombed it. Annoying support characters really don't help the show either. An unsatisfying ending was also a big factor in ruining this show's potential.
I would say it's worth watching, but it's more fun to just imagine how the show ended, rather than watching the actual ending. Then again, everyone has different tastes, so the ending may appeal to some viewers.
