Tropic Thunder – an action/comedy lampoon of a Vietnam action movie gone awry – would seem worth the price of admission just to see Robert Downey, Jr. in blackface, but Robert Wilonsky's Village Voice slam does give one pause: "When it isn't tossing softballs at the studios, Tropic Thunder is the very thing it parodies: a wall of noise engulfed in flame... Stiller is back in the send-up business, nibbling gently at the soft,......