The first spaceship to Venus crash lands off the coast of Sicily. The only survivors are Col. Robert Calder and a metal tube containing a sample of life from Venus. A boy comes into possession of the container and sells it to a zoologist for the price of a cowboy hat (like the ones they wear in the country of Texas). The monster (called an Ymir) hatches from its slimy cocoon and begins to grow at an amazing rate. When it hatches it is no bigger than a doll, but within a day it reaches the size of a fully-grown man.
20 Million Miles to Earth: 50th Anniversary Edition isn't a movie you watch for plot - you watch it for Ray Harryhausen's special effects. Harryhausen is a master of stop-motion animation and has served as an inspiration for thousands of special effects wizards. 20 Million Miles really shows off Harryhausen's stop-motion skills and why he is considered a master. It isn't enough that he makes a clay statue move on screen and blend with live action elements, but that he also manages to make it interact incredibly well while also bringing personality to the monster.
While the Ymir's chaotic trip through the streets of Rome is neat, it isn't as much of a visual highlight as earlier encounters. One of the earlier high points comes when the Ymir encounters a farmer who, in his scared stupidity, attacks the Ymir only to have it pounce on him and savagely beat him. Later on, the Ymir encounters an elephant, showcasing another great-looking fight.
On more than one occasion, the Ymir is described as a docile creature; he only fights when provoked. Harryhausen manages to get this across through the Ymir's body language. At times you almost feel sorry for the monster as it wanders around the Italian countryside. It's obviously scared and confused as to where it is. It also doesn't help that everyone it encounters either wants to lock it in a cage or kill it.
When he originally shot the movie, Harryhausen wanted it to be shot in color, but due to budget reasons he couldn't, forcing him to shoot it in black and white. The 50th Anniversary Edition features both the original black and white version as well as a colorized version, which Harryhausen oversaw. I'm typically not a fan of the colorization process, though the process used on 20 Million Miles is better than others I've seen. There are moments where the colorization is a little unnatural, though this is only really noticeable during night scenes or in random places (like Calder's hair). I still prefer the black and white version, though if you're someone who has to see movies in color, it looks good.
Of the multiple features found on the two-disc set, the best is easily the commentary by Ray Harryhausen, who is joined by Phil Tippet (RoboCop) and Dennis Muren (Jurassic Park), who talk about the special effects process in general as well as discussing Harryhausen's techniques. If you are at all interested in movie special effects, this should cement your purchase as it is a must have. There's also a conversation between Harryhausen and Tim Burton, though I personally found it bland (besides, I'm not that big of a Tim Burton fan - so I admit that may have something to do with it). John Landis, Rick Baker and Terry Gilliam also share their thoughts about the movie and Harryhausen.
For anyone interested in special effects, 20 Million Miles to Earth: 50th Anniversary Edition is a must buy. Even if the movie's plot isn't something that catches your interest, the wealth of features that deal with the processes that go into special effects is worth the price.