Recalling the cliffhanger TV series of the 1950s, Captain America: The First Avenger establishes the origins of one of the most popular superheroes from the Marvel Comics stable. Admittedly, director Joe Johnston has an arsenal of state-of-the-art digital effects at his disposal to spruce up the old-fashioned ideals in Christopher Markus and Stephen McFeely’s script.

But there’s something rather charming about the underlying themes of self-sacrifice and valour, and a chaste romantic sub-plot between the strapping hero and his feisty dame that never strays beyond a kiss. Only the sadistic killing spree of the central villain — a Nazi officer with a burned-off face — warrants the 12A certificate.

Captain America opens in the present day with the discovery of the wreckage of a gargantuan craft, then flashes back to 1942 Norway. Diabolical German officer Johann Schmidt (Hugo Weaving) steals a Cosmic Cube belonging to Odin and charges mad scientist Dr Arnim Zola (Toby Jones) with harnessing the Cube’s power as part of his plans for world domination.

Meanwhile in America, German defector Dr Abraham Erskine (Stanley Tucci) is spearheading a secret programme to create the ultimate soldier. He chooses asthmatic weakling Steve Rogers (Chris Evans) as the perfect candidate. “The serum amplifies everything inside: good becomes great, bad becomes worse,” explains Erskine.

As if by magic, Steve is transformed into a muscular hunk and he enthusiastically does his bit for the Allied effort by portraying the fictional character called Captain America at rallies. When friend James Buchanan (Sebastian Stan) is presumed dead behind enemy lines, Steve joins forces with playboy inventor Howard Stark (Dominic Cooper) and officer Peggy Carter (Hayley Atwell) to parachute in behind enemy lines as Captain America and single-handedly take on the Germans. Captain America: The First Avenger is an entertaining introduction to the iconic characters, using digital trickery to impose Evans’s head on a scrawny body before his metamorphosis. Atwell makes her entrance by punching an insubordinate soldier in the face and she embraces her role as the gutsy love interest with fervour. Their final scenes together are nicely judged, echoing a tender moment from Michael Bay’s slam-bang Armageddon.

Griffin Keyes (Kevin James) is humiliated when his sweetheart Stephanie (Leslie Bibb) rebuffs a marriage proposal in Zookeeper. “I know it shouldn’t bother me that you’re a zookeeper, but it kinda does,” she responds sadly.

Five years later, Griffin is head keeper at Franklin Park Zoo, treating the animals with compassion and earning the respect of co-workers Kate (Rosario Dawson) and Venom (Ken Jeong). Stephanie walks back into Griffin’s life and throws him into a whirl. The animals, led by Joe the lion (voiced by Sylvester Stallone) and Janet the lioness (Cher), decide to break their silence to help Griffin win back Stephanie. Once the keeper recovers from the shock that the beasts can talk, he follows their conflicting advice. Zookeeper makes Griffin the butt of the jokes as he tries to be someone or something he isn’t to find true romance. Of course, he realises that he only has to be himself to win the lady’s heart while his animal accomplices screech, growl and trumpet with delight. Sandler snaffles the best lines as the cheeky primate who believes he is superior to the other animals because of his thumbs. Though Zookeeper doesn’t really cast any lingering animal magic, it has enough laughs to keep families engaged during the summer holidays.