Charlotte is an Anime that was created through a collaboration between Key and P.A. Works,A) the former providing staff for the writing; character design; and the like, and the latter doing much of the animation work.
The world of Charlotte is one in which teenagers have random super-powers, although all of these super-powers come with a downside that usually renders it impractical to use.
I don’t remember many specifics outside of the series being quite short. The one specific issue I remember is that they undid a major plot-point, which had the effect of rendering a chunk of the show meaningless.
Charlotte was the first major disappointment I’ve experienced from Key, and it currently remains the only one. This disappointment is largely the reason this article has remained empty for a while, and will likely remain empty for a while longer.
There isn’t really anything wrong with the basic idea of the series, and the series has the same ‘feel’ that other Key properties have, just that there was a severe misstep at some point during development.B)
I think the twist that the super-powers were actually a sickness could have worked, just that it was executed very poorly. If the super-powers were actually a sickness then there should have been more serious symptoms than ‘If you use your super-powers the second you lose them, you might die or seriously hurt yourself’.
The worldbuilding in general comes off as not very well thought-out, which is quite unusual when you consider that Key’s other properties have sensible worldbuilding.C) Comparatively, Munou na Nana handles this far better.
There is a manga, but I haven’t gotten to it just yet. I have heard that it’s better than the anime, but you never know with the western anime community.