Azur Lane (Chinese: 碧蓝航线) is a side-scrolling shoot 'em up video game created by Chinese developers Shanghai Manjuu and Xiamen Yongshi, released in 2017 for the iOS and Android operating systems. Set in an alternate timeline of World War II, players engage in side-scrolling shooter gameplay, using female moe anthropomorphic characters based on warships from the war's major participants. Other gameplay elements, like customizing a home and marrying in-game characters, are also present. First launched in China in May and in Japan in September 2017, Azur Lane has briefly become very popular, especially in Japan where the player count reached five million within four months after its release. Successive Comiket numbers have yet to confirm a long-term popularity of the game in Japan, with Azur Lane ranking around 10th below franchises and genres like Fate Grand Order, Kantai Collection or Virtual YouTubers. Players have voted the game among the top five on Google Play's Best Game of 2017 list for the region. Critics have attributed the game's popularity to its original and well-designed gameplay system. An English-language version started open beta in August 2018 and was released in May 2019.