The central premise, intoned by Craig's authoritative and sometimes witty narration, is that all life is connected by its need to eat and procreate. So we watch an astonishing collection of creatures all over the world doing just that, often in unexpected ways that are not only astonishing on their own but captured by the skilled cinematographers in such a way that each segment almost seems staged for the cameras. And virtually every scene makes us gasp.

In the rainforest we follow silverback gorillas in Congo, Brazilian capuchins smashing palm nuts and Jesus Christ lizards walking on water. Up in trees there are Chilean stag beetles fighting off fellow suitors and tiny red frogs caring for their tadpoles. In the sea, dolphins work out a playfully clever way to catch fish, a mother octopus gives her life for her children, and the humpback whale indulges in complex mating games. In the sky, lammergeier vultures in Ethiopia work out a way to crack open bones. And on the land we watch snow monkeys jostling for position in Japanese hot pools, komodo dragons stalking a buffalo, cheetahs hunting ostrich and a fox stalking a cliff-dwelling ibex.

There's a lot more than this, and it's assembled with fluid editing that maintains a brisk pace as well as an openly emotional tone, thanks to George Fenton's surging score. To make sure we see every detail, much of the footage is shown in super slow-motion. And there's also a lot of time-lapse photography, which is perhaps not necessary but is pleasingly eye-catching.

It's the pureness of the images that makes this film so impressive, as we continually wonder how much time and effort went into capturing each of these scenarios. And the animal's eye viewpoint makes an Argentine leafcutter ant appear the same size as a Kenyan elephant. Watching these hunters and escape artists is genuinely thrilling, as is seeing these creatures' brainy inventiveness in the midst of nature's stunning diversity. This is a rare chance to see footage like this on a big screen, so don't wait for the video.

Born at an Oklahoma primate centre in 1973, Nim was taken from his mother after only a few days and sent to live with the LaFarge family in New York. Headed up by Columbia professor Terrace, the project aimed to test nature versus nurture, and to see if a chimp could communicate with humans using sign language. To better control the study, Nim moved into a more controlled environment with trainers Laura and Bill, who after a few years are horrified when Nim is sent back to Oklahoma to live in a cage for the first time in his life.

And Nim's story takes some more turns. At the primate centre, he finds friendship with the playful hippie Bob. But when money runs out, Nim is sold for medical experiments, an event that sparks a legal case before Nim moves to a farm for rescued horses. Through all of this, there are a handful of people who genuinely care about Nim's wellbeing, and they are powerless to protect him. He died in 2000 from a heart attack.

Hearing these people reminisce, it's clear that Nim made a huge impact on their lives. Some trainers became intensely close with him, both as teachers and playmates, and they never blame him when his violent impulses cause serious injuries. Intriguingly, Nim seemed to know that he was a chimp in a human world, learning quickly how to manipulate people, challenging men he saw as a threat and clearly grappling with his wilder instincts.

Marsh assembles this with a strong sense of Nim's life story, so we are gripped to the events as they happen. Remarkably, we experience much of this through Nim's eyes, even as the film refuses to humanise him. So in the end, the film asks some potent questions without ever moralising. Whether or not it was right for these scientists to study Nim, it's clear that the way we treat animals really needs to change.

Without any real narrative, the film takes the referees' point of view at a series of big matches, as we see them in action and hear the chatter on their radio channel. We follow well-known refs including Webb from England, Rosetti from Italy and Frojdfeldt from Sweden before, during and after the matches, witnessing the interaction behind the scenes as they support or sometimes second-guess each others' decisions. The film quietly traces the championship using a variety of languages as the refs interact with players and officials, and we also see Webb's and Rosetti's family members back home as they on their referee stars.

This unfussy film is cleanly assembled from sharp footage that cleverly catches each aspect of a referee's job. We see the refs deal with pre-match jitters in a variety of ways, including intense physical workouts. And afterwards, we follow them into a series of debriefings. It's clearly a high-pressure job, drawing strong abuse from everyone on and off the pitch, including death threats from disgruntled fans (Webb is the subject of national rage from Poland).

Clearly a very thick skin is required to be a referee at this level of sport, and these men have a confidence that makes them fascinating characters for a documentary. So does their top-athlete level of fitness, and several of them have movie-star looks. They're such strong figures that we are gripped by the way they talk to each other in the locker-room and, especially, to players on the pitch.

Still, there's not much in the way of analysis here. What makes the film so watchable is the way it takes us into this secret world so we can see how referees, managers, officials and even players get ready for the matches, deal with the politics of sport, and revisit matches on tape to refine their role. In other words, it's essential viewing for football fans.

In 1987, Mitch and Eddie moved from Wisconsin to San Francisco and rented a flat. Within a few days, their neighbours kicked in with such a hilariously over-the-top argument that Mitch and Eddie decided to record them in case the police needed them. Then the ongoing shouting matches between Ray and Pete became so compelling they had recorded 14 hours of material in a year. Copies passed to friends turned into an underground hit, leading to comic books, samples in pop songs, a stage play and film deals. But who owns the rights to this material?

The doc begins as Mitch and Eddie recount their experiences living in the "Pepto-Bismol Palace" next door to Ray, Pete and occasional flatmate Tony. In some ways the film peaks too soon, since this material is so wrenchingly funny. Even when it turns nasty, we can't stop laughing at the foul-mouthed excesses of these drunken men. The rest of the film traces the tapes' wild popularity, the growth of offbeat artistic projects around them and the attempts to track down Pete and Tony (Ray died in 1992) both to get permission and to answer nagging questions about their relationships.

And as it progresses, big issues just keep piling on top of each other. Through comments from a variety of artists, writers and producers, the question lingers: is artistic creation the act of recording or the words that were spoken? Is it fair to exploit surreptitious "audio verite" recordings, or are they in the public domain since the conversations were audible outside? And why was Ray, a "bitter homophobe", sharing a flat with the clearly gay Pete?

The film is assembled with a lively sense of humour that plays up the story's mysteries while observing events with a sense of irony. Watching it is thoroughly entertaining as it shifts through various layers of comedy, investigation and drama, all with a hilarious surfer-dude attitude. And we're surprised as we go to discover that we're thinking almost as much as we're laughing.