Beleaguered aliens, who have naively based their entire society on intercepted transmissions of a cheesy sci-fi series, land at a "Galaxy Quest" convention in search of war heroes. What they get are tired TV icons including a hungover prima donna (Allen), a fading buxom beauty (Weaver) and a bitter, classically trained actor forever trapped beneath latex headgear (Rickman).

The starving players think they’re committing to an autograph session when, in fact, they’re being recruited to fight big, mean, scaly space Huns. By the time reality hits, they’ve already reached infinity and beyond. they encounter laser blasts, mine fields, odd creatures and a nebula full of genre clichés beamed up for sly comic effect.

With PG films rare, parents of younger children may find Galaxy Quest tempting. Use caution. Sci-fi violence includes childlike creatures voraciously turning on a wounded peer. Aliens are shot, blown up, beheaded, tortured, turned inside-out and sucked into space. The dialogue is set on stun with a dozen TV-grade profanities and a flagrant misuse of God’s name. And in the final 15 minutes, everyone is upstaged by Weaver’s cleavage.