Animal Treasure Island turned out to be quite a nice little adventure, and for something made in 1971, it holds up really well. The story follows the rough outline of the original novel it's based on with obvious liberties taken around every corner. I haven't read the actual book but I've seen 3 or 4 different adaptations by now and it's been fun to spot the similarities along the way. The only major departure seems to be a boy meets girl element when Jim meets Kathy. Can't really complain about it cause it's added in quite naturally and their relationship is rather cute. This kindof stuff is also pretty common in anime when dealing with this type of story.

The presentation is where this adaptation really shines though cause its relatively short runtime for a movie is chock full of various visual gags and action scenes. It's all not only creative, funny, and well-choreographed, the animation is excellent as well. There's really a lot of expression in how characters move and act, I think any animation fan would enjoy this for the craft alone.

There's also some decent musical numbers peppered in throughout but I didn't find them quite as good as other parts of the movie. The only standout is a sequence where Jim and Kathy discuss what they'd do with a treasure and it culminates in a musical scene with pretty dreamy visuals where their imaginary ship floats through abstract backgrounds and places where they'd want to go.

Overall it's a pretty easy recommendation for anyone who liked adventure stories, old anime, or animation. It's a great example of a movie that's obviously intended for a younger audience but can still be entertaining well outside that age group.