“Unbelievable” (** out of four) was an uneven sci/fi comedy about martians conquering Earth and how a team of astronauts and concerned citizens (Snoop Dogg, Garrett Wang, Chase Masterson, and others) attempt to thwart and stop them with the help of powerful plants of marijuana. Cheeky premise is played to the hilt with occasionally amusing resultsm just not enough to sustain a feature-length film. Cheech and Chong could have made this same movie- and funnier- about 30 years ago. Michael Madsen plays the President named Ben Dover, if that gives you a sense of the movie’s sense of humor.