With the first three Ice Age movies having grossed over two billion bucks at the global box office. The usual characters — Manny (Ray Romano), Diego the soft-hearted sabre-tooth tiger (Denis Leary) and Sid the idiotic sloth (John Leguizamo) — are cast adrift on an iceberg, with Sid’s senile but resourceful granny and — voiced by Jennifer Lopez — a feline love interest for Diego. They have an adventure out at sea battling big waves, bad pirates and treacherous sirens before reuniting with Manny’s family. These are not the funniest or most interesting characters, but there’s enough humour and danger to make this the second-best of the series, after the initial Ice Age. Continents drifting apart can’t help but make everyone a little nervous — and this Ice Age turns into a fully constituted and respectably delightful episode in what has, so far, been an altogether rollicking series. Let’s remember that digital animation — 3-D or not 3-D — has made full-length animated films among the greatest entertainments of the movie age we’re living in.