VLC is the sort of software where if it can’t play it, I don’t know what else could. I guess I’d also try the ffmpeg command line tool to see if it can figure out what the video file even is, and maybe it could convert it to a regular format.
Also TBH such a video file would be interesting enough that you could probably post it here (if possible, or any metadata you can extract from it) and see if anyone knows how to play it.