Who can tell me how it works-video bullet screen games !!

I was shocked when I found such a bullet screen game on a video website called blibli.

I have never seen this interactive and game-filled video. The user wasd can control plane movements to avoid subtitles, and the number of deaths in the top left corner of the subtitles can be counted. Subtitles are not in a single direction, it also contains the motion track, which also contains collision detection !? Maybe I know too little about it. I really think it's amazing. Which IT experts can explain how this is done !?? (The Link is shown below)

Click Open Link

:

It's amazing !! Video address:

Http://www.bilibili.com/video/av1029730/

It is best for Apple to open it in safari.

If anyone knows how this is done, please don't hesitate to give us some advice. I have never touched the webpage and the interactive video production. It's amazing ~

Please leave a message at the bottom of your blog to help me solve the problem. Thank you first.

Who can tell me how it works-video bullet screen games !!