Like Super 8, this astringently funny coming-of-age odyssey from writer-director Richard Ayoade is set before the era of cellphone cameras. Submarine ups periscope on Oliver Tate (the hypnotically morose Craig Roberts), a 15-year-old Welsh fantasist who sees his life as a home movie, creating scenarios that include his death. There are no monsters, unless you count the leatherboy life coach (Paddy Considine), whom Oliver thinks is shagging his mum (Sally Hawkins) and driving his dad (Noah Taylor) deeper into depression. He forges letters from dad to mum formally requesting sex. Hilarious. Except for a desire to sacrifice his cherry to Jordana (the wonderfully acerbic Yasmin Paige), his pyromaniac lust object, Oliver lives in his head. You can’t trust a word he narrates. Ayoade, the British comic making a remarkable feature debut with his adaptation of Joe Dunthorne’s 2008 novel, blends mirth and malice with deadpan brilliance.