Edinburgh’s 39th Film Festival got off to a good, glitzy start over the weekend with a gala performance of the Spielberg-produced, Robert Zemeckis-directed Back to the Future, which has made so much money in the States this summer that a quarter per cent of its net profit would set up the likes of you and me for life.

All we can do, though, is pay to watch it - well actually I’m paid. And though it is hardly one of the greater flights of cinematic imagination to be seen since science fantasy reared its head as mass appeal material again, it would be virtually impossible not to enjoy it in some way or another.

The combination of Spielberg as ideas man and Zemeckis as executant (the latter made the efficient and at times ingenious Romancing the Stone) is just right for this story of an ordinary guy transported back in time to the mid-Fifties, and faced with his parents as teenagers. Spielberg supplies the sentiment and Zemeckis pours the acid, so that nostalgia is laced with a little provocation.

It doesn’t go as far as Gremlins, because Joe Dante really is spiteful, whereas Zemeckis is only playing at it. But the moment the ordinary guy’s mother takes a lunge at him in her bedroom, without knowing he is her son, is at least one sequence to cherish.

A spot of unknowing incest, which of course never comes off, suggests that this is not the bland leading the bland. Actually, it’s the boy genius leading us gently by the nose again. Highly entertaining, but that’s about all.

Derek Malcolm reviews other films, including Subway, Brewster’s Millions and Desperately Seeking Susan, at the Edinburgh Film Festival