Forget ‘Blue sky on Mars’, beads of sweat and other puzzles; the real ambiguity in this film is the physical impossibility of Arnold Schwarzenegger.  He doesn’t look like a construction worker or a spy and, if you were being fanciful, his presence (in all senses) could let you argue that the whole film is an implanted memory.  The 2012 remake had a load of great ideas (Rekall as an opium den, ‘the Fall’ – an elevator between England and Australia, John Cho) but Colin Farrell just looks like some guy and there’s no real doubt.

Beyond the head scratching and smarts there is a lot of grown up sci-fi fun to be had here.