It's an abbreviated version of
Warren Ellis' "All-Star Superman" comic series. Condensing it all down made it a little disjointed, but it's a great adaptation nonetheless.
What's particularly sad is that the guy who adapted it,
Dwayne McDuffie (one of my favorite DC writers), just passed away really unexpectedly the other week. Aside from adapting All-Star Superman into a movie, McDuffie was one of the producers, lead story-editor and one of the writers of the Justice League and Justice League Unlimited animated series, as well as the show-runner for 'Static Shock' (which was based on the character, Virgil "Static" Hawkins, who he had created for his own Milestone Comics).
He celebrated his 49th birthday on February 20th, then went into the hospital the next day for heart surgery, and died of complications from the procedure. All-Star Superman came out on the 22nd.