“Sunny with a chance of creatures” could well be the weather report from the world of Monsters, one of the most startling movies of our new DIY filmmaking culture. British FX designer Gareth Edwards, making his feature debut as a writer and director, took a tiny team — himself and four other crew members, plus his two stars, Whitney Able and Scoot McNairy — to Central America to improvise an off-the-cuff, on-the-road journey through a world, not very far removed from our own, in which aliens have arrived and settled in and humans barely pay attention to them. Journalist Andrew (McNairy) is asked by his boss to escort his daughter, Samantha (Able), home to the U.S. from Mexico, and they get detoured through the quarantine zone separating the two nations, a sort of impromptu preserve where the giant squid-like alien animals are (mostly) contained. The usually gee-whiz stuff is relegated to the background or quickly elided over — such as the fact that the ETs arrived on Earth via a NASA probe, which brought their DNA back from one of those intriguing moons on the outskirts of our solar system — in favor of letting us see how humans have adapted to their presence… which becomes a parable with how our culture deals with most crises: some violence, some acquiescence, and a lot of simple coping that soon becomes subsumed into the everyday. (I love the cartoon on the TV in the background of one scene, explaining to kids the importance of wearing the gas masks when the U.S. fighters are bombing the monsters nearby.) I wish the romance that develops between the two protagonists felt more urgent and plausible than it does, but this is a forgivable lapse. I love this movie for dealing with one of the questions I always have at the end of alien-invasion movies: “Okay, but what then?” This then.