Enterprising programmers were able to produce games for the ZX81 using nothing more than text characters and the machine's limited text semigraphics. Some ZX81 games achieved lasting fame, such as "3D Monster Maze", a tense first-person perspective game that involved the player escaping a labyrinth with a Tyrannosaurus rex in pursuit. Written in a combination of BASIC and machine code, its innovative design led it to be hailed as the first home computer 3D game and a landmark in the history of computer and video games.