Go, Speed Racer!
First, set aside everything you know about movies. Set aside everything you know about cars, or racing, or the laws of physics. They don't apply.
Second... if you're epileptic, do not see this film. Don't even drive past the theatre. God never intended for there to be that many colors, and certainly would never have contrived a scene where they all appear at once. Imagine, if you would, that Willie Wonka went stark raving mad, tied you down in his lab, and poured jellybean dye directly onto your eyeballs. That's not dissimilar to the experience of watching this film. From that perspective, this Day-Glo festival of horrendous hues is most certainly a work of the Devil himself.
But once you get past the lurid Dr. Seuss colors and impossible physics you find that the story itself is not bad. And if you grew up a child of the '60s (like me), you'll find that everything you loved about the cartoon is here. The Wachowskis (yes, the Matrix people) make no attempt to change or delete anything. The iconic theme song is used copiously, and all of the characters are exactly what you expect... no surprises there.
Plotwise... Speed has been obsessed with racing his entire life, and after his brother dies in a cross-country race, Speed takes up the mantle of driver for his family racing company. He's offered a spot as driver for a Big Company, and when the deal turns sour, it's up to Speed to make things right and ensure that Truth and Justice prevail, etc., etc., yada yada yada. OK, so the plot's been used a million times. It's how you tell it that counts, and this is done pretty well.
The casting can't be faulted. Emile Hirsch is Speed, looking for all the world like he was drawn from the cartoon, Elvis pompadour and all. John Goodman is Pops Racer, wrestler-turned-mechanic (a bit of trivia they actually use in the movie!). Susan Sarandon is Mom Racer, who is perpetually stuck in the 1950s like a fly preserved in amber. Christina Ricci as Trixie is hotness on a stick; she's never looked cuter. Matthew Fox turns in a credible performance as "Racer X"; Kick Gurry is Speed's mechanic "Sparky"; and Paulie Litt steals the show as Spritle, Speed's younger brother (with the help of a chimp).
Now, a sensible reviewer would blast the movie for the glitz, the colors, the senseless motion. But somehow all of this works, IF you forget that you're watching live action and treat it like the anime that it is. This is not a movie, it's a live-action cartoon. Mukokuseki abounds. What year is it? What country are we in? Who gives a rip? It's a timeless, multi-cultural romp.
I'm no fan of the Wachowskis. I, for one, look on the whole Matrix series as a not-so-subtle uncredited rip-off of Jack Chalker's Wonderland Gambit trilogy (The Cybernetic Walrus was released in 1995; The Matrix in 1999). So it pains me to admit that I actually liked Speed Racer. The jury is still out as to whether it's a work of genius or insanity. But it is, as I said, entertaining.