What if Red Dwarf were given a big budget and re-made "Backwards"?
I'm only teasing a little bit! It is impossible to do a good Time Travel story. The closest I've experienced is "This Is How You Lose the Time War" which, similar to TENET, has sort-of-spies chasing each other through time.
Most sci-fi movies are an excuse to advertise the prowess of the special effects team - and TENET is no exception. Even on a TV screen, it is blisteringly clever the way they seamlessly interweave the forwards and backwards running shots.
The plot... Well, no spoilers, but if you seen any time travel film you'll guess what's going on about two minutes before the film reveals it. I actually think that's the mark of a good screenplay - the audience should feel ever-so slightly more intelligent than the protagonists.
And, again, like every other time travel film there is some thundering exposition to get through. Having Michael Cain read from cue-cards directly into the camera isn't exactly the best use of his talents - but it gets the job done without too much fuss.
A word on the sound design. It'll give your subwoofer a good workout - explosions and a thumping soundtrack. I know a lot of people complained about the mumbling dialogue - but I didn't find it worse than any other movie. Maybe turn the volume up on the centre speaker and kill the bass a little if you're worried.
As a James-Bond film - all gadgets and bloodless violence - it's a success.
As a spy-thriller - hunting the McGuffin - it's flawless.
As a sci-fi film - with extensive temporal shenanigans - it's a mind-bender.
As a social object - to get you chatting about what really happened - it's a triumph
Definitely worth experiencing.