Previous to this documentary, I had seen several of the other animal documentaries by Disneynature, and I thought they were pretty good. However, this time around things don't work out so well. It's not an awful movie; there are some good things to be found here and there. The Sri Lankan scenery is colorful and attractive to the eye. The photography is also well done (see this movie, if you must, on Blu- ray!). And you do get to learn some interesting things about the particular kind of monkeys the movie showcases.
However, while the previous Disneynature movies were presented in a way that adults could enjoy them alongside their kids, this is not the case this time. There is an often juvenile feeling to this documentary. The Tina Fey narration is quite often cloying and childish, and several times the mood is spoiled by the soundtrack playing loud pop songs. Just as big of a problem is the direction at times. It's clear that several situations are staged and manipulated by the filmmakers. This might have been because there isn't that much story or drama elsewhere. Even though the movie runs about 81 minutes, it sure feels slow at times.
There have been much worse documentaries out there, but in the end this particular one is strictly kids stuff. It will entertain your kids (at least if they are in a patient mood at the time), but if you want to watch a documentary with your kids, pick one of the other Disneynature offerings.