Popular mobile games and short-video apps in China are competing for the attention of millennials, but a little-known smartphone game called "Party.io" becomes a sudden hit in the country after users posted videos while playing the game becomes viral on Douyin - a short-video app known as TikTok worldwide.

The mobile game is now the most downloaded free game in China for Apple users, and it had also surpassed previous leaders such as the PlayerUnknown's Battlegrounds (PUBG). Party.io becomes popular thanks to viral videos of users posted on Douyin, which has over 500 million users.

Players in Party.io can control a playdough-like figure, and it would grab its enemies and then throw them off the arena - ranging from a birthday cake to floating houses to hot air balloons. Basically, the last player standing wins.

The dough-like figures fight and fall in a wacky way, and they gain in size with the number of kills. The controls in the game were easy: tap the screen to control the direction while drawing infinity symbol "∞" to snatch other players and throw them away.

China's internet has popularly known the game as the "Douyin game about throwing people." One user of the short-video app shared a 15-second clip of him winning the game after getting five kills. The video has received almost 2,000 likes.

Although Party.io displays gamer IDs, as well as their national flags, players can currently compete against computer-controlled characters. Roster Games developed the Party.io; it is a small studio based in Turkey.

Party.io ranks as the top iOS game in two dozen countries at the moment, including Ukraine and China, the South China Morning Post reported. However, the game doesn't make it to the top 30 in the United States. Meanwhile, short-video apps such as Douyin and Kuaishou were among the popular trends to young people in China, which was previously dominated by mobile games and live-streaming sites.

Due to their popularity, the country recently published new censorship rules for short-video apps. The first rule indicates all video content - including introduction, title, and viewer comments - should be reviewed before being broadcasted. All companies involved in the short video business were also required to set up a content reviewing team with a strong political sense.

Pornography and sexual content, such as kissing, caressing, sexual moaning, and other sex-related depictions are not allowed in videos as well. Users were not also allowed to make short clips and animated images from speeches of national leaders or mimicking their dress and gestures.