There were two stories told in this episode: one about Wataru's (Kiva's human character) in present day, and another one about his mother which happened back in '86, before there was Kiva. On Wataru's side, the episode had the potential to turn into a comedy instead because of Wataru's imagination about his allergies to this world. The story about his mother though, was more serious, as she was shown fighting against the Fangaias almost all the time.
Apart from Kiva's armor design, the action in this episode was really cool. I didn't watch much Kamen Rider these few years, so I won't compare Kiva to any of them. But the fight scene really reminds me of the old-school-punch-and-kick cartoons I like to watch. That's right, no second Kamen Rider, no weapon, just Kamen Rider one-one-one with his Fangaias opponent.
Kiva's 'Henshin' (transformation) is rather simple, but his ultimate move, Darkness Moon Break, is totally awesome! The name of his move wasn't explicitly mentioned though, it was called 'Wake Up' when his belt Kivat was activated for that move.
I'm really looking forward to the next episode. Looks like I have another series to keep myself busy with apart from Gundam Double O ^^