Minecraft in his performances. A simulation of the game was featured in Lady Gaga's "G.U.Y." music video. The game is also referenced heavily in "Informative Murder Porn", the second episode of the seventeenth season of the animated television series "South Park". "Luca$", the seventeenth episode of the 25th season of the animated sitcom "The Simpsons" was inspired by "Minecraft"; Persson responded by tweeting "I'm not sure how I feel about it." After the release of "Minecraft", some video games were released with various similarities with "Minecraft", and some were called "clones" of the game. Examples include "Ace of Spades", "CastleMiner", "CraftWorld",
Minecraft meters above in-game sea level. "Minecraft" has also been used in educational settings. In 2011, an educational organization named MinecraftEdu was formed with the goal of introducing "Minecraft" into schools. The group works with Mojang to make the game affordable and accessible to schools. In September 2012, MinecraftEdu said that approximately 250,000 students around the world have access to "Minecraft" through the company. A wide variety of educational activities involving the game have been developed to teach students various subjects, including history, language arts and science. For an example, one teacher built a world consisting of various historical landmarks for