Let me first of all frame my review by saying I'm a massive fan of the original movie.
I hadn't even heard of this until I accidentally stumbled across it on Apple TV, and given that my partner has never seen the 1981 original (disgraceful, I know) I thought we should give it a whirl.
This is absolutely not a remake of the film. Most of the story beats are there, but it is otherwise completely different and is very much aimed squarely at kids, with some adult humour thrown in. Admittedly it starts off... not great, just ok, but stick with it for a few episodes and it becomes very funny, especially the episodes with the neanderthals and Mansa Musa.
It doesn't have the comedic genius of Gilliam and Palin, but I enjoyed it as its own thing, and not just an updated version of the much loved film.
It helps if you're a fan of Jemaine Clement (Flight of the Concords) and Taika Watiti (What We Do in the Shadows) as their humour is pretty off the wall and improvised, but if you're a curmudgeon who says things like "in my day blah blah blah..." then you'll probably moan about this.
If you have adolescent kids, you won't really go wrong here. If you enjoy offbeat, stupid humour you'll have some fun. It's not amazing, but it's much better than it has any right to be, and I had a pretty decent time watching it.
I have minor hope for a 2nd series, but we'll see.