Aoi Sekai no Chuushin de

, also known as World War Blue, is a Japanese manga written by Anastasia Shestakova and illustrated by Crimson.

Plot
Segua Kingdom has been losing the war against Ninterdo Empire but the tables are turned by the appearance of a boy called Gear. All the characters are parodies of Nintendo or Sega games such as Sonic the Hedgehog, Super Mario Bros., The Legend of Zelda etc.

Official

 * Official Site (Japanese)

Other Sources

 * Wikipedia
 * Anime News Network (Manga)
 * Anime News Network (Anime)