which was modified to suit fighting games. In the first Injustice development diary, NetherRealm Studios proclaimed that several technical advancements had been made since the release of Mortal Kombat in 2011. Sanchez stated that their "KoreTech team" had pushed the boundaries on their graphics engine. Urbano added that the game features a revamped lighting solution, enabling more dynamic lighting in terms of characters and environments. A new "character material" system was created to portray characters with increased graphical detail. Injustice also utilizes a multi-threaded rendering engine, allowing the game to display approximately three times the amount of objects on screen at a single time than Mortal Kombat. Marketing Prior to the game's release, Warner Bros. Interactive and DC Entertainment launched a 10-week-long online marketing campaign called the Injustice Battle Arena. The web series, hosted by Taryn Southern, featured weekly match-ups between the playable cast in a tournament-style format. Each week, the arena was updated with different versus scenarios. Fans could vote for their favorite characters, and a video, depicting the winner of each round, would be released following each voting period. Videos detailing the skills and strengths of the combatants, including vox pop and celebrity interviews, were released alongside each new pair of challengers. Voters could redeem free rewards, ranging from Xbox Live avatar accessories to a downloadable character skin based on Green Arrow's appearance in the television series Arrow. Participating fans based in the United States were also eligible to win weekly prizes. A demo version of the game was released as a download for the PlayStation 3 and Xbox 360 on April 2, 2013, in North America, and April 3, 2013, in Europe. The demo showcased Batman, Wonder Woman, and Lex Luthor, in the Gotham City stage, with Doomsday as an unplayable boss. Release Injustice: Gods Among Us was released on April 16, 2013, in North America, April 17 in Australia, and April 19 in Europe for the PlayStation 3, Wii U, and Xbox 360. Certain Australian retailers, including JB Hi-Fi and EB Games, broke the street date, selling copies on April 15, 2013. The release of the Wii U version of Injustice was delayed in the United Kingdom until April 26, 2013. The game was released later in Japan on June 9, 2013, for the PlayStation 3 and Wii U. It was also added to the Xbox One's library of backward compatible Xbox 360 games in December