Just got back from it. I honestly can't say what to think of it. At times it's exactly what the movie should be, and at times it's an awful mess, and it's hard to pinpoint the blame. In a sense it's the worst and best of Shane Black too. The screenplay is self aware and overly ironic, and often does too much to play with genre tropes. On the other hand Black always understands the little things that make movies tick, and it's often that if you feel he kept things simpler, he would've achieved much more here.
Olivia Munn is hilariously miscast and is only saved by the fact that the movie moves at such a rapid pace that after her first couple scenes you don't really get the room to think about how terrible she is. It also helps that the rest of the cast was clearly having a lot of fun with this. Yes, there's a ton of shytty lines, and a whole lot of not-good-enough actors to make them work, but they're all strangely committed and on the same page. When the action hits it's brutal enough but the pacing doesn't really do much for building suspense, most of the action blending into a slasher/shootout hybrid filled with explosions. Some of the kills are inventive though and reveal that somewhere they definitely got the right idea, but never managed to work it out into a fully functioning movie, and that's a shame.