I haven't seen it freeze like that after a specific time, but the game does have a user input mode that is either on or off, depending what is happening on the screen. The cursor changes to a spinning wait cursor during those times when the user isn't able to interact with the screen, which means it will ignore clicks. There was a bug at one point where it would end up in that mode and never come out. I thought I'd fixed that though. Does it happen every time for you at 2 minutes? If so, has the mouse cursor changed to a waiting cursor?
Something that might be happening around the 2 minute mark is the background music finishing. At that point it sets the position back to the start and plays it again. I guess it might be possible that this hangs on some browsers, on some machines. I'm using a JS library that emulates the OPL2/3 chips, e.g. as used in the Adlib/Soundblaster sound card from 30+ years ago. It generates the music on the fly with a web worker thread.
What browser were you using? I only tested on the latest Chrome to be fair. I know that some of the css effects don't work too well on Firefox. Also older versions of Edge lose a lot of the css effects. The newest releases of Edge that use the "Blink" engine handle things better. It works reasonably well on Chrome on mobile phones.