The 2012 documentary's selling point is that they've managed to bring back all the major players involved in the original 1992 show's production: the producers; the director; the writer; the primary cast members.
Not that you'll have any idea who any of these people are - unless you're a child of the 80s/90s. There's no real introduction to these famous faces, in particular an understanding of just how well known they actually were and why. Surely it was their level of celebrity - and the implicit trust imparted in them by the audience - which was a primary reason for the original show's shock value?
So good luck any Millennials or Gen Zers watching this doc to find out what the fuss was all about, particularly as new faux-factual shows are broadcast and cite 'Ghostwatch' as a forebear (EG 2023's The British Miracle Meat).
Additionally, save for some sporadic personal photographs, it's let down by an absence of any footage from the original programme, contextual or otherwise. I highly recommend watching 'Ghostwatch' itself (available to stream on Amazon or buy on DVD/Blu Ray) before diving into this. Otherwise, if you've only watched that one-and-done broadcast 30+ years ago, if at all, you may quickly become disconnected from this arid series of talking heads.
This disconnection is further compounded by the editing. The doc runs at a glacial pace and even the chapter title cards (seemingly incongruous unless you've recently rewatched) linger on screen longer than they should.
With additional context, including footage (even stills would be beneficial) and more discerning editorial choices, this could be condensed into a tighter and more engaging show.