Minecraft led to Persson becoming one of "Forbes" "World's Billionaires". "Minecraft"s music and sound effects were produced by German musician Daniel Rosenfeld, better known as C418. The background music in "Minecraft" is instrumental ambient music. On 4 March 2011, Rosenfeld released a soundtrack, titled "Minecraft – Volume Alpha"; it includes most of the tracks featured in "Minecraft", as well as other music not featured in the game. The video game blog Kotaku chose the music in "Minecraft" as one of the best video game soundtracks of 2011. On 9 November 2013, Rosenfeld released the second official soundtrack, titled "Minecraft – Volume
SethBling missiles at each other and trying to blow them up". In Missile Wars, players receive items which they can use to spawn missiles, and blow up, stop and defuse incoming missiles. Players can jump on missiles and ride them across the playfield. Cubehamster said that "subtle techniques" involving missile mechanics had made the game popular. According to Cubehamster, Missile Wars was built in two weeks and thoroughly tested afterwards. The game was featured on Minecraft Realms. As a nod to Microsoft's 2014 acquisition of Mojang, SethBling recreated basic functionality of "Minecraft" in Microsoft Excel, which included navigation and crafting. In