Right at the beginning, we are implicitly promised an answer to what energy is, but alas, the show never gives it. Instead, it changes it focus after the midpoint to entropy.
Now, there is a definite answer, and physicists know even if most of the public does not, but the film never even it touches upon it (for the curious: look up Noether's theorem).
Also, for something billed as "the story of energy" it is quite incomplete. Potential energy (Leibniz's "dead force") is never mentioned, and radiation and mass-energy are only alluded to in the most indirect terms. If anything, it should have been billed as the story of *thermal energy*, but even as such it is so incomplete as to be misleading.
The film implies that Boltzman came up with kinetic theory, but in fact Daniel Bernoulli did about 150 years before him; the link Joule established between mechanical and thermal Energy, Loschmidt's role in pointing out the difficulty in linking entropy to time, and Gibbs' achievements in organizing our modern understanding of statistical mechanics are all left out.
The film does have nice visuals, and some of the physics concepts and historical contexts are laid out in an engaging way, but in the end it feels like a bait and switch: we get entropy instead of energy, and the illusion of understanding, whether it be historical or physical, instead of the real thing.