For the English localization of the game, a new, lower difficulty option was added for players who want to focus on the story and puzzle-solving, and the game balance and the user interface were tweaked. Swimsuits that were available as downloadable content in the Japanese version were also changed to be available in the base game in the English version. Some content had to be changed to be able to release the game on Steam and PlayStation 4 in the West, such as tweaking scenes where a character's underwear could be seen, and removing or changing scenes featuring child characters that could be interpreted as sexual. The cover art for the PlayStation 4 version also had to be modified to meet public storefront display standards. "Zanki Zero" was met by mixed reviews, ranging from average to positive, according to the review aggregator Metacritic. The game's PlayStation 4 and PlayStation Vita versions were the fourth and seventh best selling games of the week during their debut week in Japan, selling 15,541 and 9,111 copies, respectively; the PlayStation 4 version sold another 4,164 copies during its second week, bringing total physical Japanese sales of the game to at least 28,816. The PC version was among the best-selling new releases of the month on Steam. Sir Tristrem  Sir Tristrem is a 13th-century Middle English Romance of 3,344 lines, preserved in the Auchinleck manuscript in the National Library of Scotland. Based on the Tristan of Thomas, it is the only surviving verse version of the Tristan legend in Middle English. Microbacter margulisiae  Microbacter margulisiae is a Gram-negative, anaerobic, non-spore-forming and non-motile bacterium from the genus of Microbacter which has been isolated from sediments from the Tinto River in Huelva in Spain. Manor of Silverton  The manor of Silverton was an historic manor in the parish of Silverton in Devon. The last version of the manor house was Silverton Park (also called Egremont House), a large neoclassical mansion house built in 1839–45 by George Wyndham, 4th Earl of Egremont (1786-1845) and demolished in 1901. It was according to Pevsner and Cherry (1991) "an extraordinary design, entirely clothed in colonnades",  but was "a monstrous Italian house" in the opinion of Bernard Coleridge, 2nd Baron Coleridge (1851-1927).