However I found it grew on me. There was a lot of padding (helicopters for the sake of helicopters, for instance), and the whole plot would barely have filled 45 minutes of New Who. But it picked up once birdsflying arrived to sort things out. I've written about dodgy accents in this story before, but even Van Lutyens started sounding more Dutch (or at least less like anything else) as the story went on. And it's a pleasant novelty to have a Who story in which everyone survives.
Victoria's departure - the Victoria/Jamie relationship was an opportunity never taken up by the programme's writers (or, interestingly, by fanfic writers). Jamie clearly fancies her rotten in The Power of the Daleks, and at the end of the first episode of The Ice Warriors he is trying to persuade her to wear the more revealing fashions of the locals (when their conversation is interrupted by the waking monster). But nothing more seems to have ever been made of it. NB that the next two female companions (Zoe and Liz Shaw) were both brainy. Then back to screaming, with Jo Grant.
As Anne said as the title music faded at the end, "So the evil seaweed menace that was threatening to take over the world was defeated by a few loud noises? Not awfully threatening then, was it?"