[Guido]

As you guessed correct, this is the opening theme to Innocent Venus.

For me it's the first time to download and listen to the full version of a music theme to an anime before said song premiers on that anime.

The song starts with a low paced introduction emulating a sad and solemn (not of the religious type sang in chorus) solo, and immediately picks up at a fast, rhythmic pace on combination of soft rock and j-pop blended with classical overtones of violin and cello renditions to give it gothic qualities and several techno tunes arranged.

Actually, there were few instance peaks in the melody that made me imagine as if I was listening to the songs composed and performed by ALI Project, particularly Hikari no Sansenritsu, Rozen Maiden Traümend's OP theme.
Even another similarity on how the music plays when the song starts, that it quite resembles to the music of Shingetsutan Tsukihime's ending theme, Rinne no Hate ni.

Noble Roar makes a lot of emphasis to the classical melodies on the score, especially violin and cello, henceforth, the opening theme never loses its goth-classical tempo.

I rate it with a 100%

Changing the topic....

After rewatching the subbed version for episode one, I felt the character animation more resembles to Eureka 7 especially to the detail of the colorful, shining eyes on the main cast. However, the post-apocalyptic scenery of a devastated Tokyo strongly reminds me to Akira.

It's interesting the writers choice for as the apocalyptic trigger became a series of natural atmospheric phenomena cataclysms or Hyper Hurricanes rather than the all too traditional end of the world by nuclear warfare.
This evokes a similar apocalyptic theme touched in Roland Emmerich's film, The Day After Tommorrow.

However, there's always the likeable possibility that Hyper Hurricane phenomena was due to mankind's continuous intervention on the planet that triggered the partial extinction event established in the anime's storyline.