Where to begin...
The gameplay has been so perfectly refined in the years the franchise had been going that it's simply the best platformer available on any console. If you've never played the series before, it's a good place to start, though it does follow on directly from the previous two so you might want to pick those up first. If you're looking for a new platformer and are having doubts, read on...
The gameplay is a seamless blend of platforming, action combat and puzzles, each intensifying as the story progresses. When I played the first of the PS3 R&C titles the thing I was mostly impressed by was the sheer amount of information the screen could handle at any time- bolts (in-game currency) flying everywhere, enemy fire coming in from all sides, the level of destruction is vast and handled smoothly by the console. Imagine facing a horde of thirty-odd enemies, dodging fire while dealing out some of your own, all while facing an ever-dwindling supply of health thanks to some nasty nerve toxin. That's just one of the game's combat challenges (mandatory, mind you) that adds a different flavour to the usual run-and-gun, encouraging a kind of absolute concentration that's initially tricky to master but thrilling to execute. Most interesting of all though are the Clank levels, in which you often have to record your own actions and then replay the levels in tandem with the recording(s) in order to achieve multiple targets, all in under a minute. These are the game's one true innovation, and are as frustrating to figure out as they are rewarding to complete.
The game's humour is the best of any I can remember, from the always-hysterical Qwark's myriad one-liners ("keep the change, villain!" and "it's like time is all...not working" among the best) to the constantly apologising robots ("WE.WERE.JUST.KIDDING.WOULD.YOU.LIKE.TO.GO.FOR.SOME.PIE?"), or Dr. Nefarious' screaming for his butler LAWRENNNNNNCE and the various assorted aliens aping actors as* diverse as Woody Allen and Peter Lorre. I also picked up references to Seinfeld and Star Trek among many others. In addition to the humour there's a few moments of genuine sadness too, owing much to the game's exploration of family and in particular, fatherhood. Deep stuff.
Graphically, it's at least the best looking game of it's kind of this generation, only less impressive than those games that go for photorealism. Each of the game's planets looks nothing less than amazing, from the nuclear winter of the Tombli Outpost to the heatstroke haze of the Molonoth Fields. The planets are sprawling, vast landscapes with distinctly non-linear paths that encourage exploration for collectables such as bolts, weapon schematics and upgrades. This is extended with the addition of the moon levels, essentially mini levels focused entirely on platforming or combat. It would be easy, given their skewed camera angles and gravity allowances, to criticize these as Super Mario Galaxy rip-offs, but let's not forget that Ratchet and Clank games had been set in space for years before the portly Italian set his sights on the skies, so it was an inevitable conclusion. Speaking of the emptier regions of space, Tools Of Destructions' on-rails shooting sections have been abolished in favour of free roaming sections that allow you to explore for side missions and enemies for levelling up.
While the score is suitably orchestral if underwhelming, the voice acting is second to none. Jim Ward's Captain Qwark I've already covered, though Dr. Nefarious gives him a run for his money as the series' best character. Kudos to Armin Shimerman (surely familiar to Buffy fans and Trekkies), whose throat must have been wrecked when the recording sessions were done. The rest of the cast give it their best too but these characters are beyond praise.
In short, everything from the previous PS3 titles that could be improved upon has been. In terms of length, it took me a good 20 hours to finish the main story, although that was a very thorough run through on the hardest difficulty. Still, it's a refreshing break from the standard 12 hour run-throughs that we accept these days as long as there's multiplayer bundled in. Platinum trophy hunters ought to wrench (hohoho!) another week out of it, too. Quite simply the best platform game ever made.
*Have you ever SEEN such alliteration!