Having seen various stage versions of this farce over the years, including the original West End run, the film makes you realise why it should remain a play - its the 'being there' factor of live theatre that gives it immediacy and magic. Some action also takes place in the auditorium, brushing by the audience itself, so you can really feel the panic and desperation of the characters on stage as they strive to deal with mounting chaos, struggling to maintain face and professionalism, despite ludicrous interuptions to their efforts. The script is sublime, and so finely constructed, (and technically breathtaking), that the play is still going strong in provincial theatres all over the UK today.
If I hadn't seen the stage version, the film may have had more impact, but I felt dissapointed. Obviously, you cannot replicate that theatre experience, despite the excellent cast, Michael Caine and Christopher Reeve, but I was willing to see it. I can't see myself watching it again, so I would say 3 stars out of 5.