Dr Faustus, Cottesloe Theatre, NT London

I don't usually need a crib-sheet at the theatre (no, that isn't me you've seen with the large-type Tales from Shakespeare), but I was glad to find, after seeing The Wonderful Life and Miserable Death of the Renowned Magician Dr Faustus, that there was a "resource pack" available on the internet. It wasn't the plot that confused me - I just couldn't understand who and what this play was for, and why it was at all.

The notes for teachers explained that Marlowe's play was so popular in Germany, the source of the Faust legend, that there were many locally rewritten versions, including some for puppets. This, then, is how the adapters Rebecca Gould, Mervyn Millar, and Carl Grose got the idea of splicing their hour-long Faustus (directed by the first two) with the tale "Sausages of Doom," in which a naughty puppet sells his soul for a saveloy. The National Theatre's Education Department has gone to town to get in the half-term parents and children with its suggestions of how Faustus can help not only "literacy strategy learning outcomes" but geography, history, art and citizenship. Encouraged to "develop a sense of creative ownership" of the story, the sprogs could rewrite it, showing how one or another character might have made better choices, and giving their own recipes for turning lead into gold.

Gould, Grose and Millar may not have had those aims when they constructed their Dr Faustus, but they have certainly done everything they can to undermine the play's beauty and terror, a strategy that, to judge from the other educational productions I've seen at the National Theatre, seems to be the official one. Of course, it may simply be taking its lead from a school system in which the classics are occasionally deemed elitist and irrelevant. The most basic aspects of Marlowe's play are skimped or smudged. Got up in red tights and a low-cut Elizabethan man's costume, Emma Stansfield looks less like Mephistopheles than a wench at a 16th-century Hellfire Club. Faustus (Guy Lewis) is no hubris-mad hero but a weedy young chap in shirt, tie and tank top, whose only reward from his pact with the devil is Helen of Troy, a dressmaker's dummy in a chiffon scarf. "How can she make you immortal with a kiss?" my inner child piped up. "She hasn't got a head." God makes a brief appearance, but little awe is inspired by a deity who wears a white fedora and talks like Simon Callow.

It seems to be evidence of a worryingly divided self for the National Theatre to be trying to attract young theatregoers to one part of its building while, in another, younger ones are bored and puzzled by a witless parody of theatre. To quote the only line from the play that got me, O Education Department, where I live, if you say you have no sin, you deceive yourselves.

To 25 February (020-7452 3000; www. nationaltheatre.org.uk). Also tonight at the Albany, Deptford, London SE8 (020-8692 4446; www.deptfordnet.org.uk) tonight