"Blast From the Past" is a sunny, good-natured romantic comedy that is as light as the air, but almost always charming, and is helped immeasurably by the occasionally sharp screenplay, written by Bill Kelly and Hugh Wilson (also posing as the director), and the uniformly strong cast of relatively fresh, young talents and veteran actors.

The film starts out in Los Angeles in 1962 at a party being held by the Webbers, scientist Calvin (Christopher Walken) and the 9 months pregnant Helen (Sissy Spacek), when they hear word about the oncoming Cuban missile crisis. Quickly getting rid of their guests, Calvin and Helen desperately make their way down into their own personal fallout shelter just as a plane crashes in to their house. Thinking the Big One hit, Calvin sets the locks for 35 years because, as he says, by that time the radiation will have faded. Equipped with every possible thing they could need, Calvin loves the life down in the shelter and as the years fly by, teaches his son, Adam, as if he were in a real school. Helen, however, eventually begins to go stir-crazy, turning to any alcohol she can find, even her cooking sherry. Ultimately, 35 years finally pass and the Webbers decide to send Adam, now a grown man (Brendan Fraser), up into the world for the first time. Losing his way back to the fallout shelter, which a slummy restuarant run by a hippie has been built on top of, all Adam really wants is a girl, which he finds in the form of Eve (Alicia Silverstone), a cute, but cynical, young woman who is at first distant with him, but agrees to help him in his quest of buying and storing as much food as possible, thanks to selling his nearly priceless 35-year-old baseball cards. Eve is not really sure why he is doing such a thing, but doesn't bother to ask since, after all, he is so unlike all of the men she has known before, and is more like an innocent boy, albeit one that is not used to the '90s world.

Although "Blast From the Past" often feels somewhat like "Pleasantville" in reverse, "Blast" mostly avoids the latter's serious commentary on the world and so it is inevitably not nearly as deep, but because of this, also does not fall into the trap of laying the emotions on too thick.

Undoubtedly a romance at heart, the film was therefore surprising how, in the first half-hour, the characters of Calvin and Helen were the main focus, and it had a wonderful start, thanks to Walken's and, especially, Spacek's bright performances. Spacek is usually seen in more dramatic pictures (as in the remarkable recent "Affliction"), but shows that she is also a wonderful comedian, and a standout in every one of her scenes as the loving wife and mother who happens to also be going into a hilarious descent into booze.

Once the now-grown Adam takes over the film, "Blast Fom the Past" is transformed into an entertaining "fish-out-of-water" story, as he starts to discover the world, including the sky and ocean, which he has never even seen before. One small, but sweet sequence shows Adam sitting at a window and intently watching the sunrise for the first time in his life.

As a budding romantic comedy, the film is also a success, due to the charming rapport between Fraser, who seems to recently be switching from indies ("Gods and Monsters") to the mainstream ("George of the Jungle"), and Silverstone, who has made her first good film since she appeared in 1995 in one of the best comedies of the decade, "Clueless." Although certainly nowhere near that level, it is a clear improvement from her last two failed excursions, the embarrassing "Batman & Robin" and the misguided "Excess Baggage."

For all of its many engaging elements, "Blast From the Past" is in no way anything more than merely good. The film is slight, but in a fun way, and makes no excuses for being anything more than what it sets out to be, a winsome, frothy comedy. Throughout the film, I laughed out loudly quite a few times, and was won over by the pleasant two lead characters whom I wanted to both be happy. The movie delves no further down than this, but that was quite enough for it to be an entertaining diversion for 106 minutes.