The colorful fantasy car racing scenes are magical, but they’re also emotional, because the underdog main character’s victory is a victory for Justice itself. Speed Racer demonstrates that integrity matters, that you can win by being honest (though not by being naive), that cheaters, in fact, never prosper in the long run. It’s not subtle. It’s not realistic. But it has an awesome kind of purity. There’s nothing quite like it.
It scrambles the timeline in the sequence at the beginning, which seems like genius to me now that I know who all the characters are and where the plot is going, having seen the movie several times. It probably didn’t make nearly as much sense the first time through.
See below for a detailed plot summary with SPOILERS in the form of a beat sheet in the style described in Blake Snyder’s Save the Cat.
BTW, this story perfectly fits the Save the Cat genre called “institutionalized,” in which the main character encounters a group or a system and has to join, escape, or destroy it.