Eidolon

The player discovers the Eidolon, a strange 19th-century vehicle in an abandoned laboratory. As the player investigates this device, he is accidentally transported to another dimension and is trapped in a vast, maze-like cave. The creatures in this cave, sensing the energy emanating from the Eidolon, are awakened from a long slumber, and the player soon finds that his only chance of survival lies in this mysterious vehicle and its powerful energy weapon.