It's a visually impressive series and has some good moments, though it's definitely a Dark Magical Girl show, and to me the TV series has an unsatisfying ending -- I found the continuation movie (Madoka Magica: Rebellion) more enjoyable for its willingness to take a whack at some of the tropes of self-sacrifice that frustrated me in the series. The mobile game, though, has some very sweet moments -- not least because it seems to focus on overcoming the despair and isolation that make magical girls self-destruct -- and there's lots of room for fic.