The Belko Experiment managed to accomplish the difficult feat of never being boring, not even for a minute. It takes almost no time getting going, and at any given moment it is either action packed, or taking a break from action and descending into dark humour. Both of these were well-executed, with one particularly memorable action piece (the end of round 2, so pretty), and a spattering of interesting side characters, a lot of them hilarious in either attitude or demeanor. With that, it managed to entertain throughout, making it worth seeing.
However, where it fails is originality. The Battle Royale formula has been done time and time again, and here we get the straightest form of it, with zero deviation from the norm and zero unique perspective. Where a movie like Circle tries to infuse some kind of basic examinations of social themes, here there is no higher level to the killings. And for this, the movie never once surprises with a thought or an event. The characters are just shells of people; the bad guys are caricatures of evil, the protagonists of good. There is never ambiguity of character, in a movie where so much moral ambiguity should be present due to the situation. So from minute one you know exactly who will be a villain and who will be a hero, and the end game is obvious from the start. It's a waiting game for the movie to arrive where you know it is going, which makes it very unsatisfying once the action is over.