So, new titles, new TARDIS, new outfit, old voice for K-9 in the brief moments he has on screen before he stupidly heads into the sea to get shorted out (but hooray! John Leeson is back)... and new incidental music, as it turns out. Instead of the familiar sounds of Dudley Simpson, we get synthesizers from the BBC Radiophonic Workshop (and Peter Howell in particular -- the man who also redid the theme tune). It's a bold new sound for the show, and one that's honestly quite welcome; not to disparage Dudley Simpson at all, but it is nice to have some fresh blood.
The whole thing also looks different too. The leisurely (sorry) pace that characterizes the first couple of minutes of the show continues throughout. This isn't an action-packed, frenetic story; instead, first-time (and last-time, as it would turn out) Doctor Who director Lovett Bickford chooses to use lots of slow-yet-constantly moving shots to give things an almost sensuous feeling (well, as much as a story about plant people running a tourist haven while fending off a takeover from reptile people can be sensuous) -- and this is aided by lots of handheld shots and unusual (for Doctor Who, at least) framings, with extreme close-ups and out-of-focus foreground elements often the order of the day. Plus, set designer Tom Yardley-Jones has (presumably at Bickford's request) elected to put ceilings in most of the sets. This means both that Bickford gets a lot more low-angle shots, and that even the lighting is different as a result, which just continues to add to the feeling that a new and different stylistic change has occurred.
Of course, the problem with these first two installments of The Leisure Hive is that there's not actually much going on story-wise. We learn a bit about the Argolins and their Leisure Hive, and about the war that led to the downfall of their race ("How long did the war last?" the Doctor asks Chairman Mina as they look out over the radioactive wastes of Argolis. "Twenty minutes," she replies. "As long as that," says the Doctor, somewhat impressed), and we know that something (almost certainly a Foamasi) is skulking about the Hive causing problems and killing people. Oh, and there's an Earth scientist named Hardin who's playing about with experiments involving tachyonics (a real theoretical field involving faster-than-light particles) and time. And that's about it. There are so many elegantly-paced shots and camera moves that it occasionally feels like they're trying to make up for the slight plot, and with Tom Baker and Lalla Ward both firmly reined in as far as humor goes, it does come across sometimes as rather dull.
Still, two great cliffhangers: the first shows the Doctor apparently being torn apart and in agony (something of a shock for those who'd become used to the untouchable Doctor of recent seasons), and then, after an experiment in tachyonics gone wrong, his coming out of the Recreation Generator cabinet looking incredibly old and decrepit. The superhuman Doctor is, it seems, a thing of the past...