Doom (1993 video game)
The ability for others to create custom levels and otherwise modify the game using WAD files turned out to be a popular aspect of "Doom". Gaining the first large mod-making community, "Doom" affected the culture surrounding first-person shooters, and also the industry. Several future professional game designers started their careers making "Doom" WADs as a hobby, among them Tim Willits, who later became the lead designer at id Software.
Doom (1993 video game)
In 1995, "Next Generation" said it was "The most talked about PC game ever – and with good reason. Running on a 486 machine (essential for maximum effect), "Doom" took PC graphics to a totally new level of speed, detail, and realism, and provided a genuinely scary degree of immersion in the gameworld."