I didn't have high expectations going into this movie, having seen more than my fair share of awful direct-to-video horror films, but I ended up being pleasantly surprised by Lockout. It's clearly a low-budget movie, but the director and actors prove to be fairly adept at working within those parameters and still coming out with an intriguing, competent little film. In that way and several others it reminded me of the little-seen German serial-killer movie Schramm (1993).
There were some flaws here that prevented Lockout from falling into that "great but unknown" category. While the acting is far above par for this kind of movie, a few scenes did fall a little flat. The pacing could be a little tighter overall. And at the end of the movie there's a sort of big reveal which isn't particularly compelling (or unexpected, by the time it happens).
Overall the dialog is much better than I would have expected, though, from the naturalistic-sounding phone call in the first scene to rest of the character's conversations. The focus of the movie tends to be on the characters and their emotional state, rather than the larger plot, and as such it tends more towards evoking unsettled moods over outright shocks and scares, which is fine with me. It also has a few thematic subtexts that are more complex, and better executed, than is common in the genre, although some of these seem a bit muddled up by the end of the film.
I'm not much of a gore-hound myself, but there is one fairly graphic gore scene. I think the director was wise to concentrate his effects budget in a few places instead of just hurling red paint everywhere, but the level of violence is probably not enough for voracious gore-hounds and a little extreme for the more typical horror fan.
Overall this one is definitely worth a look, especially if you are a fan of more cerebral, low-key horror. It's certainly much better than the 3.2 rating it's currently hovering at.