Nazca refers to the Nazca Lines, a series of geoglyphs located in the Nazca Desert, a high arid plateau that stretches more than 80 kilometres (50 mi) between the towns of Nazca and Palpa on the Pampas de Jumana in Peru. This geoglyphs have odd shapes, which have been taken as mystical or work of UFOs in more than one oportunity. Many videogames and anime make use of this myth, as you'd guess, including Ryuusei no Rockman 2, Yu-Gi-Oh! 5D's, and now, Kamen Rider Double.
Ironic that Takenoko mentions bitching about Akiko when, for once, I actually enjoyed her character. Mainly because of how she got Philip to stop thinking about his family by telling him how Shoutarou wanted to protect him. It was kind of cute.
Luna-Metal is epic. It turned a metallic bo into a whip. That's just too awesome. Heat-Metal, once again, gives the finisher, a good thing in my opinion, as Metal Branding > Joker Extreme.
So, Kamen Rider has meaning once again in this series, and now it's not something as odd as a guy who fights others like him in a world inside of a mirror, a worker for a destroyed company or one that uses a bug-shaped thing and can go at the speed of light. Now, it's literal, a guy who is on a bike and wears a mask. I like how it was introduced, and how Shoutarou and Philip reacted to it. Rather than saying "man, she got our name wrong!" as has happened in more than one series, they accepted the title, and even quoted the previews.