Wurm: Journey to the Center of the Earth (Chitei Senkou Bazolder in Japanese, or Vazolder: The Underground Battle Space) is a 1991 NES title developed by SOFEL Co., Ltd and pubilshed in North America by Asmik. The game is a sci-fi action title that spreads multiple modes of gamplay across its stages. It was designed by Hiroshi Kazama and Shouichi Yoshikawa, who had both previously designed Golgo 13: Top Secret Episode.
The story is set in a sci-fi future version of the year 1999. After a series of unusual earthquakes, crews of VZRs, or special vehicles designed for drilling deep into the earth and exploring underground, are sent to investigate the cause. Moby, the eighteen-year-old leader of one such VZR crew, is the protagonist of the game. She and her crew-mates discover that two underground races exist deep beneath Earth's surface and are at war with each other.
As stated above, the game features multiple modes of gameplay.
There are two types of stages in which the VZR is piloted. There are side-scrolling stages and vertical-scrolling stages. In each, the player must watch both the VZR's shield energy and fuel, as running out of either will result in failure. The player can drill through rock barriers and fire a weapon to deal damage to enemies. In the side-scrolling VZR stages, the player can also switch the VZR between drill and hover modes.
When not piloting the VZR, the player takes control of Moby directly in side-scrolling levels. She can move left and right, jump, and fire her weapon as a standard attack. She also has a kick as a melee attack that can be used by pressing Up on the D-pad.
The Boss stages in Wurm take place from a first-person perspective. How close the player is to defeating the enemy is depicted by a possibility meter. Before the battle begins, Moby is allowed to talk to her crewmates about the coming fight. Doing so will increase the base possibility value at the start of the fight, and talking to specific characters in a certain order will raise this possibility more than others. Once the fight starts, Moby can deal damage to the enemy by lining a reticule on it and attacking. As damage is dealt, the possibility meter will increase. Once the meter reads 100%, the next strike on the boss will defeat it.