The lead character from the first movie takes a backseat somewhat, making way for the cyborg friend and former lover, and to a lesser extent, the lover's clone, as well as to multiple other key characters. It's an interesting concept actually, and I haven't seen it explored before: that the clone looks and acts so much like the former lover presents a challenge, and the conflict is apparent, but not overdone.
The director, who also directed the first movie, has worsened his obsession with beautiful people. There's a lot more of them here, although I did really like a senior representative of some weapons manufacturing company named Poseidon. She's presented with greater admiration than the lead.
The action does not offer any real improvement over the previous movie, even though the budget is 3 times as large. It's also not as interesting. The animation is of more consistent quality than the first movie, but there's nothing really groundbreaking.
sidenote: Why the fuck did they have to drastically change the physical look of Athena (basically the president of the city) so much? She's not even recognizable.