Following on the heels of the animated "Monsters Vs. Aliens," "Alien Trespass" (opening April 3 at Landmark's Hillcrest Cinemas) covers somewhat similar ground. Both films present us with an alien who comes to earth and then the films try to use the trappings of 50s sci-fi movies to sell the premise. But unlike "Monsters Vs. Aliens," "Alien Trespass" is live action. It also comes from R. W. Goodwin who should know what he's doing since he worked on the cult TV show "The X-Files," which frequently dealt with aliens although usually in a more serious vein.