there were The Carpet People
This was Terry's first novel and, well, you can sort of tell. It is still wonderfully written and there is the trademark humour he has so wonderfully carved out as his own, but it was definitely not his best. There were ideas and characters and the imagination that can all be found somewhere in Discworld, so if you've read those you'll feel like you're tucked up in a familiar duvet. And if you've read those, you'll be so in love with Terry you won't mind that at all.
It is written well, as previously said, and the pace was so quick I couldn't often keep up, but the humour is so forced sometimes it definitely brings you back down to the reality that this is not a Discworld and not a good one. The imagination of creating a tiny race of people that live in the deepest, darkest parts of a carpet is wonderful, but as with a lot of fantasy I had trouble with getting behind the mix of Real-World terms and Made-Up-World terms. Most fantasy places have some form of cow or horse and a lot of fantasy books will make up a new word for this animal, even though it's obviously a cow or a horse, because what you're actually reading is a (use your imagination) translation of this story from it's original language (the Made-Up-World language) in to English. So even if it's not called a horse there, it will be called a horse in the book. In terms of The Carpet People
the mix of Real-World and Made-Up-World creature names was annoying and confusing.