Snail Maze

Snail Maze is a 1986 maze video game developed and published by Sega for the Master System. Instead of being released on a cartridge, it was built into the BIOS of the non-Japanese versions of the console and could be played by starting the system without a game cartridge inserted and holding Up and buttons 1 and 2 simultaneously, consequently being a launch title for the console in the region. Some later console models included a minimal BIOS because of memory constraints, and Snail Maze had to be removed. These systems instead included a built-in Alex Kidd in Miracle World or Sonic the Hedgehog. Snail Maze was not released in Japan.