I can't really add much to what has been said about this game already, except to say that I simply found it virtually perfect. The writing is absolutely beautiful, consistently funny, and often surprisingly moving. That is partly because Grunk, as a character, has such integrity and believability. Although presented as incredibly dense, the way he describes locations and objects, often incorporating quite shrewd observations along the way, suggests that he's not all that stupid at all. That gives him depth and emotional resonance. It must be said also that by having Grunk narrate the game in its entirety offers a neat approach to the problem of who the parser is supposed to be, and whether the narrator of the game is a different person from the PC. This game solves that problem by identifying the PC with the narrator, although at the cost of distancing the player from the PC (if Grunk is telling me what's going on, I'm clearly not Grunk, just in case I'd had any uncertainty on that score). There's no emotional distancing though, because Grunk is so engaging a personality.
The puzzles are nicely logical and the gnome NPC has a dry, educated wit that meshes perfectly with Grunk's rather more straightforward approach to life. There are a truly vast number of things you can ASK GNOME ABOUT, most of which have no bearing on the game itself, although some of course contain vital clues. It's a lot of fun to explore these topics, although this can result in the gnome seeming a bit like one of those information-dispenser sort of NPCs who are inexplicably willing to be grilled at length by over-curious PCs. But the gnome's sardonic wit and the fact that he's busily doing other things whilst satisfying Grunk's curiosity make him much more than a talking pedia.
The pig also has a lot of character, making this whole thing rather like one of those children's books that adults can also enjoy. I liked the author's attention to detail, which often brought out extra little elements of the characters (e.g. try taking your trousers off in front of the pig). I must admit that having apparently completed the game I was puzzled by how to gain the elusive last point and looked it up fully in the hints. I rather wished I hadn't, not only as it would have been more fun to work out by myself, but also because the behaviour required to get the last point is the sort of behaviour that I instinctively engage in when playing this sort of game anyway, but generally don't bother, because it seems not to matter. The fact that it mattered in this game says a great deal about it. This is a game with heart.