"zone of the enders: the 2nd runner" also includes an unlockable 3d remake of the original "gradius" arcade video game called "zoradius". in "zoradius", the player uses the vic viper in fighter mode, flying through a tunnel and shooting down various non-humanoid enemies from the game to gather powerups to increase the viper's firepower and shields. roughly halfway through the stage, the player has to fight through an area full of ring-shooting moai heads, also a staple of the gradius series. the game ends in a boss fight against the train boss, also from the main game. the music and sound effects used in zoradius are taken from the first "gradius" arcade game, composed by miki higashino.