The double entendre of the title -- a reference to Cold War atomic detonation as well as a common cliché -- is the most clever thing about Blast From the Past, a fish-out-of-water comedy whose original premise is a lot less airtight than your average fallout shelter. Brendan Fraser may not play a cartoon character, as he's basically done in Dudley Do-Right (also directed by Hugh Wilson) and George of the Jungle, but those admittedly marketable skills are just as over-modulated as ever. Equally cartoonish is Alicia Silverstone, though more for her appearance than her whiny acting style. As the former teen star transitioned uncomfortably into her adult years, she developed a puffy, collagen look. That leaves Christopher Walken and Sissy Spacek as the best things about Wilson's film, and they regrettably disappear for its middle portion. Walken's comedic skills, demonstrated during numerous stints hosting Saturday Night Live, have been tragically underutilized throughout his career, and Spacek seems to have fun with her own vacation from dramatic work. More of their eccentric parenting and less of Fraser's naïve pratfalls through modern existence might have broken down some of the formula -- but probably also narrowed the film's popular appeal and its status as an accessible romantic comedy. As Silverstone's homosexual sidekick, Dave Foley gets good laughs by trusting his instincts to tone down the flamboyance expected from such a role.