Specials are often comical imitations of the real show, and I don't think anybody typically has an objection to that. Occasionally it is nice to have some light-hearted humor after a particularly deep or "heavy" series.
To be honest, though, it didn't work here. Perhaps, the largest reason it didn't work was a result of the way they began the specials. The first episode was full-length and had anything you would have come to expect from the Accel World series, albeit almost entirely detached from the main plot-line. It wasn't especially good but definitely met the standards of the original series, and I would have enjoyed the rest more if it had continued that way.
But then, for some strange reason, the creators decided to take what could have been a fulfilling group of sequels to Accel World and turn it into an ugly amalgamation of poor humor and characterization. I'm not an expert on anime (far from it), but I personally think it's a bit stupid to switch to "children's book animation" (because I don't know the damn word for the art style) when you've laid groundwork for a solid set of episodes.
Considering this is likely the last thing we see of Accel World, I'm extremely disappointed that the high-tension, extremely emotional chaos will be replaced by cutesy crap forever in my mind. What aggravated me the most was Lotus/Hime's portrayal as being both arrogant and fairly stupid. Anybody who saw the original series knows that Black Lotus is perhaps the most epic character. How a writer could sit and replace that perfectly seductive yet shy, wise yet absent-minded, and stubborn yet humble girl with such a gross parody will forever amaze me.
