Stop it. Just stop it. Put down the Sony Handycam before someone gets hurt. This is yet another piece of sub-sub-standard torture porn (although even the lowest grade of porn surely isn't as dull, mechanical and narratively uninteresting as this) in which an apparently random group of people are brought together in a darkened, cavernous location and forced to participate in the twisted games of a maniac with a philosophy - for a film which isn't a rip of Saw, but a rip of various Saw sequels (notably Saw 2 and Saw 5). That's not intrinsically a bad thing, if it's been made by people who know what they're doing, but again: when it's been made by talentless amateurs it is almost physically painful. And it goes on and on and on for damn near two hours.
The thrust of Death Tube is that there's a Japanese snuff website run by a psychopath who likes to dress up as Pudsey Bear off the BBC charitythons - I am not making this up - and kill people if they fail his idiotic challenges. Eight strangers wake up in sealed-off cells and have to not just solve a Rubik Cube against the clock but perform faintly humiliating or painful acts over a webcam before proceeding to the next level. Gradually the group are whittled down as they try not just to survive the games, but to work together to outwit Pudsey and his minions. Some of the challenges are stupid (an indoor obstacle course including hopscotch and carrying a tower of bricks), some of them nasty, and all broadcast live over the internet with viewers' comments overlaid across the screens.
We're not given any reason to give a hoot about any of the participants beyond one-line soap-opera backstories - one's about to get married, one's awaiting his first child - and we're not given any information about the maniacs either: we never get to see who's in the Pudsey suit and why. Technically it's incredibly shoddy, with the sound levels changing between shots and the bulk of the movie overlaid with an abominable score consisting of synth performances of popular classical music. It's ugly to look at, shot on ungraded video in a dull location, it's far too long and it doesn't work on any level at all. Once more: if this is the best you can do, don't bother.