It had potential but blew it..
This may contains spoilers
Story 5/10 : Why 5 ? The main reason of this is the big flop at the 12th episode..
The idea of being trapped in a video game was an awesome idea, this is why I first watch the anime. But sadly, this thing lasts only 14 episodes.
The second arc is really unnecessary, it's basically what ruined the whole anime for me. Starting with a "warriror" thing to end with a fairy thing.. Just WTH ?!
Art & Sound: 8/10 At least, the chara-design and the soundtrack were good.
Characters : 5/10 Well, during the 1st arc, I'd give a 9/10, but the 2nd.. Kirito.. Crying all the the time.. just no.. And the SM hair fetishist guy.. *facepalm*
Enjoyment : 5/10 Like for the characters, I enjoyed the 1st arc, but the 2nd, I just forced myself to watch the end of this anime..
Overall : The 1st arc was perfect and it probably be better if it was the only arc..
The 2nd arc is just a waist..
Without the 2nd arc, I'd probably give a 8-9/10