 Complete the following phrase:  As games became more realistic, issues of questionable content arose. The most notable early example is NARC, which through its use of digitized graphics and sound and its adult-oriented theme quickly became a target of the press. These same issues arose again when Mortal Kombat debuted, particularly with its home video game console released on the Genesis and Super NES platforms; due to Nintendos strict content-control guidelines, that systems version of Mortal Kombat was substantially re-worked to remove any extreme violence. In response to these issues and in parallel to similar demands made upon the music and movie industries, the ESRB was established to help guide parents in their purchasing decisions. 1993s Doom caused quite a stir, with its detailed 3D graphics and copious amounts of blood and gore. The 1996 game, Duke Nukem 3D, was accused of promoting pornography and violence; as a result of the criticism, censored versions of the game were released in certain countries. In the 1999 