W.U.R.M.: Journey to the Center of the Earth, released in Japan as Vazolder: The Underground Battle Space (地底戦空バゾルダー, Chitei Sen Kū Bazorudā?), is a multi-genre video game released for the Nintendo Entertainment System in 1991 by Asmik.
The plot deals with mysterious earthquakes, and the government dispatches explorers in powerful digging machines called VZR's (nicknamed WURMs, but the name is never used in the game). The player controls Moby, the leader of one VZR's crew. She and her friends discover that two races of subterranean humans have been fighting a war underground. More characters join the crew over the course of the game.
WURM has a variety of different styles of play, with side-scrolling travel stages in the VZR, overhead shooting levels, levels where Moby leaves the vehicle to explore underground ruins, and first-person shooting levels with boss monsters.
Source: Wikipedia, "http://www.wikipedia.com/Wurm:_Journey_To_The_Center_Of_The_Earth," available under the CC-BY-SA License.