3D Monster Maze (19xx)(J.K. Greye Software) ROM Download for Sinclair ZX81 (). 3D Monster Maze (19xx)(J.K. Greye Software) game is available to play online and download only on Roms Games. 3D Monster Maze (19xx)(J.K. Greye Software) ROM for Sinclair ZX81 download requires an emulator to play the game offline. This Game is English (USA) Version and is the highest quality available.