And the Thomas DVDs are... strange. Or at least, some of them are; and there's an odd and intriguing progression in their development.
In other series - Transformers, say, just to pick an example - there's an established set of characters with an established set of qualities: skills, weaknesses, personalities, and looks. Periodically the series will undergo a reboot, and at that point the characters (and perhaps the entire setting) will be given new qualities, a new look and feel, and perhaps a new story dynamic.
Thomas and Friends, however, doesn't seem all that concerned with consistency. Insofar as there's an actual "reboot", it seems to come in the transition from the written stories to the television (and later movie) episodes. Even so, the early videos draw heavily from the stories. These are actually my favorites: they tend to be short and episodic, often with a little moral homily (but not too heavy-handed), and they're filmed entirely using model trains and tracks - no CGI. Even the people in them are just little wooden models. And they manage brilliantly using just those resources. They're also extremely consistent about the characters - their personalities, what they do, how they talk and interact.
A bit later in, you can see where the producers started cleaning some things up to make the show more appealing to American (and possibly just modern) audiences. The Fat Controller becomes "Sir Topham Hatt". Some of the more pronounced accents disappear. It's just a few little changes, and easy enough to ignore.
But you can also see where they started to run out of source material. The Rev W Awdry and his son Christopher only wrote so many stories. And the writers who produce the scripts for later episodes are very obviously not the same people; they aren't as obsessive about the details of railways, so you have some episodes where (I'm fairly sure, though I can't cite an example) engines who were previously confined to Narrow Gauge Tracks now freely roam about the standard-width rail lines. They also don't have the same feel for the characters and dialogue: Gordon, for example, is still presented as Proud and Strong (and occasionally a bit conceited), and he still pulls the Express; but the Gordon in the later episodes just doesn't sound like the Gordon in the earlier episodes.
Where it really gets interesting, though, is when you reach the feature-length movies. Because they're... different. Really different. Really, really, different. How different?
Well, despite the changes in the series across the years - and we're talking a couple of decades, here - the television episodes are consistently set on the island of Sodor. Sodor is a world unto itself, which happens to have sentient, anthropomorphic vehicles.
The first of the full-length Thomas movies, Thomas and the Magic Railroad, makes a rather radical departure in terms of both setting and story dynamic. Start with the "magic railroad" part - previously, Sodor has not had any sort of magic at all. Yes, the trains and other vehicles have faces and talk, but that's considered perfectly normal and natural. The movie introduces live-action actors, and makes Sodor into a magical other world accessible from our own - Wonderland, perhaps. Or maybe Narnia is a better comparison, since Sodor is also now threatened by the evil Diesel 10 - who was previously just a cranky, scary engine. (In the same vein, diesels and steam engines were frequently presented as rivals, but never as enemies. In fact, prior to this, the island of Sodor essentially lacked villains entirely.)
The next movie - I think; I'm a little shaky on the production sequence, here. Anyway... Calling All Engines ignores these developments entirely. It's done in the older style, with model trains, and focuses on the rivalry between the "steamies" and the diesel engines. Note, however, that there are no actual villains here; it's just a rivalry that turns into a series of pranks, which escalate until nobody can get anything done.
...And then we come to Misty Island Rescue - and we change genres again. If Thomas and the Magic Railroad is Thomas in Narnia, then Misty Island Rescue is Thomas on Treasure Island. Seriously; there's a point early in the film where Thomas is drifting on a raft at sea. He finally washes up on a beach, and his raft is perfectly aligned with a set of train tracks that run straight down the beach to the edge of the sea. This only makes any sort of sense at all once you realize that you're watching a boy's adventure story in which the boy has been replaced by a train. Even the soundtrack sounds like it's right out of Pirates of the Caribbean.
The last entry in my list - that being a list of Thomas Movies That I Have Seen - is Blue Mountain Mystery. As the name suggests, we've changed genres yet again... Thomas has taken it upon himself to investigate a tragic incident that happened at the docks many years ago. (Also, several of the narrow gauge engines have mysteriously acquired what I think are meant to be Jamaican accents.)
Now, there are several other movies in there, which I haven't seen - Hero of the Rails and Day of the Diesels, at the very least - so this pattern where each new movie places Thomas in a new and different genre may not hold together as well as I think it does. But if that really is the pattern, then I have a suggestion for what I'd like to see them do next: