Don't remember much of the first game to compare, just the Doc Oc climax, that was better than this one.
I don't think the third act here works particularly well, with it's over the top scale and repetitive arena boss fights — 'This is a stronger boss, so let's make him have like six health bars so the player have to fight him six times'.
What it DOES better than the first one are the action set pieces. It has a lot more and they're all great spectacles.
That first battle at the beginning, damn, what a way to start a game!