heart, complete with arteries and ventricles. Ricardio is one of the few individuals in the Adventure Time universe to have a highly detailed face; during the commentary for the episode, his design was compared to that of the face on the moon in the 1902 French silent film Le Voyage dans la Lune, based on H.G. Wells's 1901 novel The First Men in the Moon. After the episode aired, series composer Casey Basichis posted a video explaining his inspiration and method of producing the music featured in the episode. According to the video, Basichis created a "skeleton" of the score in his shower using his voice and a ukulele; the audio was captured on a phone. Originally, the score was going to have a "New York City, taxi, and jazz" feel, but Basichis was unhappy with the genre choice, and changed the feel. For the music that played while the Ice King interacted with Ricardio, Basichis was inspired by the score from the original seven-minute short. In addition, opera singer Karen Vuong lent her voice to the episode. According to Basichis, Vuong was able to record her vocals successfully in one take. Basichis chose opera because he knew it had a reputation for being "sickeningly intellectual" and "preoccupied with murder", traits that he felt suited Ricardio. Reception "Ricardio the Heart Guy" first aired on Cartoon Network on April 26, 2010. The episode was watched by 1.91 million viewers, and scored a 1.3/2 percent Nielsen household rating, meaning that it was seen by 1.3 percent of all households and 2 percent of all households watching television at the time of the episode's airing. The episode first saw physical release as part of the 2011 Adventure Time: My Two Favorite People DVD, which included 12 episodes from the series' first two seasons. It was later re-released as part of the complete first season DVD in July 2012; commentary for the episode was also included on the DVD. The episode garnered mostly positive reviews from critics. Matt Fowler of IGN, in a review of the My Two Favorite People DVD, noted that while "the idea of a walking, talking heart named Ricardio […] who plans to cut out Princess Bubblegum's heart is potent nightmare fuel", the show nevertheless "finds a way to make that grim idea accessible and fun." Takei's appearance as Ricardio gained critical favor. Charlie Anders of io9 named Takei's appearance