This was one of my favourite 90's movies. I can't figure out what this is though? It is said to be a sequel, but I've heard reboot and remake used as well. It LOOKS like a remake, in that they use the exact same lines and follow the same plot etc as the original.
But then this line:
in July 2016, it was announced that Kiefer Sutherland, who starred in the original film, would be returning for the reboot.[12] Sutherland later disclosed that he was reprising his role from the original film, revealing that the new film would actually be a sequel rather than a remake.[4]
https://en.wikipedia.org/wiki/Flatliners_(2017_film)
would have it be a sequel. Which is weird with it copying so much from the original. I didn't see Keifer in the trailer, so maybe they are hiding a big portion of the plot.