Very well done "speculative" documentary on exploring a planet, Darwin II, with alien life forms. The documetary takes the form of a "completed" expedition and the commentators all stay in character throughout. The setup is that the planet has a lower gravity and denser atmosphere making flight much more possible. Exploration is done by balloon-like robots controlled by an orbiting mother ship.

Bottom line; Excellent animations, solid science, well thought out aliens and a surprisingly convincing story. Highly recommended.