It's Guy Pearce to the rescue as the president's daughter requires saving from five hundred convicts. In space.
One of those "Luc Besson presents" films based on a recurring dream by Luc Besson, or on an image Luc Besson found burned into his toast one morning, or maybe on a barely legible note Luc Besson's flatmate scribbled down in a bit of a hurry on the back of an old cereal packet, the concept of Lockout isn't what you'd call radical, and nor is it actually directed by Luc Besson.
The deal is that five hundred psychopathic space-prisoners have got on the loose in space-prison, for complex reasons, and the president's daughter is trapped on board the space-prison where she's been doing humanitarian research of some sort (obviously) and so the reluctant antihero must save the princess. It's sort of like if you reworked Super Mario as an Escape From New York-era Kurt Russell adventure and cast five hundred assorted thugs as Bowser, and Shannon from Lost as Princess Peach. Or even maybe like you just "reimagined" Escape From New York.
Needless to say, this would all be completely unbearable, were it not for two things: 1. bulked-up Guy Pearce is pretty awesome as the Kurt Russell style reluctant antihero and 2. everything generally zips along with such cocksure energy, there's not really time to become meaningfully grumpy about any of its bounteous implausibilities.
They don't make 'em like this anymore, except when they do and you remember why they stopped. Daft, but broadly enjoyable if you're in a charitable mood.