Paul Campbell’s review published on Letterboxd:
Thunderball is a mixed bag, and very, very messy, but not a complete disaster. The highs are as high as a man soaring through the sky with a jet pack. The lows are as low as a man scuba diving to the bottom of the ocean. Ironically the scuba is good, the jet pack is bad. The middle bits are more plentiful than they are necessary.
Thunderball's greatest asset is the underwater sections which are all well shot, lit and co-ordinated. Although they have been often maligned for going on too long, I think it's only the climactic conflict which is truly guilty of this. Nassau is the least distinctive setting for the series so far, looking a poor imitation of Dr No's Jamaica, so it's the underwater scenes which really provide the location that gives Thunderball it's own identity.
Day-for-night enthusiast Terrence Young should have quit while he was ahead though as the rest of the film is a serious step back from the smooth polish Guy Hamilton achieved in Goldfinger and this is the first Bond that doesn't look bigger than its newly inflated budget. Despite the extended duration of the the film, it feels like it has been made in something of a rush, perhaps due to the arrangement reached over its legally troubled background, perhaps to try and meet the one-a-year release schedule which was wisely ended here. Right from the opening fight we're back to obvious jump cuts within shots, sped up footage, and foley work that's so exaggerated in the mix that when Bond smashes his opponent's head through a window you expect to hear a slide trombone weighing in.
I said the jet pack was bad - I was amazed to learn it was genuine. The way it's shot is exactly the same as if there was a crane arm hoisting Connery up in the air. He should be a speck in an uninterrupted field of blue! Instead, he's kept close and always near the top of the frame.
Use of rear projection is obvious, reaching ridiculously unconvincing heights during the final fight aboard the Disco Volante, but popping up in scenes like Bond putting his helmet on before using the jetpack, and in the beach shots of Domino hearing about her brother's death. These off-location pick ups are coupled elsewhere with a huge amount of obvious ADR, with lines thown in all over the place whether someone's back is turned or they're just in medium long shot, and you start to wonder how much of the script was really ready when filming began. I know Bond films have a mania for overdubbing major characters, but here everyone is in on the act (although admittedly not to the extent I suspected when I mistook Edward Underdown for John Le Mesurier in the briefing scene ("That guy's voice isn't manly enough! Can we redo it?"))
Perhaps these additions or changes to script explain why Connery seems less focused on his role than in previous films, or maybe it's just that the plot doesn't give him any interaction we haven't seen before. Largo is a minor villain with little to offer interest. Volpe is more engaging but is killed off with a shrug of inconsequence. Count Lippe is in and out of the film in little more time than Jaques Bouvar, and with the same impact on the story. Other characters, such as Bond's associate Paula Caplan and Largo's played by George Pravda are barely established. Pravda hangs about Largo's boat seemingly waiting in early appearances for the later scene in which he can assure Domino the bombs have been disarmed off screen. What's he doing there?
Speaking of bombs, do nuclear warheads really have 'Handle like eggs' printed on the side of them? Bond's tracker capsule - why does he have to swallow it? Having made himself clearly known to Largo with his 'SPECTRE on your shoulder' talk, and of course telling everyone his name all the time, why does Bond punch Felix in the stomach for nearly saying 007 - is this a game they're playing? If Bond nearly says CIA can Felix kick him in the balls? Please?
One last grievance- escaping the Disco Volante (that name!) explosion, the film ends rather suddenly with Bond and Domino hoisted away. Of all the times rear projection was used, they couldn't fit in one last two-shot for an up-in-the-air quip to round the film off?
For all that, Thunderball still hits the marks often enough, though it dawdles between them. It occasionally appears to have been assembled from bits that were filmed around another project, but the liquid core is solid. In fact, the filmmakers seem desperate to play up this theme with bikes being shoved into ponds, assassins in the shower and bath, water jetting out of Bond's car and, we have to assume, Bond himself.
"See you later, irrigator"