who heavily criticized it for non-existent enemy AI and bad level design and found it notably inferior to Doom, and one that same year by Daemon Hatfield of IGN, who gave the PlayStation Network release of the game a warm reception, saying that while it was "dated and flawed", it was "required playing for any first-person shooter fan". Legacy Wolfenstein 3D has been called the "grandfather of 3D shooters", specifically first-person shooters, because it established the fast-paced action and technical prowess commonly expected in the genre and greatly increased the genre's popularity. Although some prior computer shooting-based games existed, they were generally scrolling shooters, while Wolfenstein 3D helped move the market towards first-person shooters. It has also been credited with confirming shareware distribution as a serious and profitable business strategy at the time; VideoGames & Computer Entertainment claimed in September 1992 that the game "justified the existence of shareware", and in July 1993 Computer Gaming World claimed that it "almost single-handedly" demonstrated the viability of shareware as a method of publishing, leading to a wave of other shareware first-person shooters. The game's high revenue compared to prior, smaller 2D titles led Apogee as well as others in the shareware games industry to move towards larger, 3D titles built by larger development teams. During development, id approached Sierra Entertainment, then one of the biggest companies in the industry and employer of several of their idols, with the goal of seeing if they could make a deal with the company. After viewing Commander Keen and an early version of Wolfenstein 3D, CEO Ken Williams offered to buy id Software for US$2.5 million and turn it into an in-house development studio. The team was excited by the deal, but had felt there was a large culture clash between the two companies during their visit to Sierra and were hesitant to accept; Romero proposed asking for US$100,000 in cash up front as part of the deal rather than solely accepting payment in Sierra stock as a measure of Williams's seriousness. Williams refused, which id interpreted to mean that Williams did not truly recognize the potential of Wolfenstein 3D and the company, and the deal fell through, causing id to decide to remain an independent company for the foreseeable future. By the end of 1993 just before the release of their next game, Doom, the success of Wolfenstein 3D led id to receive multiple calls