It started off pretty well, I had a good feeling about it as the plot started developing.

Then about half way through it got a bit tedious. At the same moment two things happened.

1) The whole rest of the film's main events (except the after-credits scene) became painstakingly obvious.

2) The film stopped being as coherent and there seemed to be a few logical gaps - either because the director realised it was too obvious, or because it was so obvious that they couldn't tell it'd stopped making sense in a local context. It felt like it was missing a few scenes that explained how things happened.

It was saved by the after-credits scene, and if the final scene was before the credits instead of after, I'd be more tempted to give it 7/10 instead.