Anyway, I'm not sure how to begin, but yes, it's a game, it's not that new, but they have a new season for it, and was just released 18 August 2011! Why not many people know about this? *cries a river*
I still don't own the game yet, I have seen everything about it! The graphics are good just so good, and characters are cute (even for me who prefers guys over girls) and the story is just great. I'm a fan of these type of games, and I'm happy NIS released an english version for this game. Unfortunately, my country doesn't sell this game yet, and most of my friends doesn't know this game.
I'm a bit sad that most people will only know something (mostly a game) if they made an anime based on it.
A sequel, titled Hyperdimension Neptunia mk2 (or Choujigen Game Neptune mk2 in Japan) was announced on April 12, 2011. It is scheduled to be released on August 18, 2011 in Japan. There has been no mention of a Western release as of yet. The sequel will contain brand new main characters, as well as returning characters, and the gameplay has been updated so as to remove the random encounter feature. New maps and a brand new world will be featured as well, and the cutscenes have been upgraded from the old 2D visual novel style cutscenes. The story focuses on the younger sisters of Neptune, Noire (Black Heart), and Blanc (White Heart) on a quest to save the goddesses after they are defeated and captured by Arfoire. The time period for the game is known as 20XX, which possibly not coincidentally, is the same time period name given to the Megaman X series. The game is due to be released as a special edition with a Purple Heart figurine, a Purple Sister figurine, a soundtrack, and an art book. It is being co-produced by Idea Factory and Compile Heart, with assistance from Nippon Ichi Software, Gust Corporation, and the recently founded company Comcept by Keiji Inafune.
-copy paste from wiki-