Elfen Lied has an intriguing premise. At face value, it looks very nice. The writing is where it hits snags, and by the plenty.

Characters range from interesting yet unsympathetic to downright flat. The non-diclonii get the short end of the stick; Kouta and Yuuka have barely any personality. Meanwhile, Nana is interesting and adorable, while Lucy is complex, but unlikable. (No, her past does not excuse her actions.) Nyu is irritatingly bland and simply moe fanservice; Bando is stereotypical and flat. Though they're the interesting parts of the show, backstories feel tacked-on and forced.

Characterization problems persist throughout the show. After one character's arc ends, her characterization and trauma are dropped for the rest of the show without explanation. Characters act unrealistically, sometimes absurdly: one almost gets strangled to death and then asks, casually, "What did you do that for?" ...Okay, really? >_>

Onto the gore and nudity. These put off a lot of people from the show, so they deserve mention. Gore was less frequent than I expected. Nudity was sometimes justified; sometimes not: the diclonii in the labs, yes; the artistic opening, somewhat; the panty shots and close-ups on breasts, no.

In production values, though its animation is mediocre, it's definitely better visually than the manga. The manga's early artwork is awful, and despite evolution, it still looks stiff. This is done away with in the anime, though the art style can be off-putting in how it contrasts with the show's tone. On the other hand, the music is very good and (usually) well-used throughout. The backgrounds are gorgeous.

It's been said that you need to look past the fanservice and gore to truly appreciate the show. I can understand that. I tried to look past it and saw poorly-written characters, a forced message, and, well, the fanservice. It's still there, sometimes at the worst possible moments, killing the mood and making one wonder what the show intends to be. Does it want to be deep? The heavy fanservice and flat characters make its message—anvilicious at its worst—feel perfunctory.

If further depth were given to the characters and the fanservice were axed/minimized, then Elfen Lied would be a much better show. Instead, it's a mess.