The number of barrage words of betta fish is online. After level 5, the number of barrage words increases by one per level. Barrage refers to a website interaction mechanism in ACG culture. Users make comments in their works, and these comments will fly over the video as flowing subtitles and be seen by other users. This comment mechanism was invented and patented by multi-player countries, and applied to its video website niconico animation, which was copied and imitated by AcFun, Billie Billie and other websites. This comment mechanism has no name in Japan, commonly known as comment, but it is called "barrage" in China.