One of the risks in making a film (all right, movie: I am a snotty intellectual, what canitellya?) that relies on special effects is that those effects can very quickly appear dated and primitive. If the film doesn't have other merits--say, a compelling story, good writing, impressive cinematography or fine acting performances--then there is little reason to watch once the effects start to look clunky.
I haven't seen it in a while, but I suspect that The Muppet Movie might escape that unfortunate fate. For one thing, I think the Muppets will always be fun to watch. For another, four decades after the Muppets graced the silver screen, one effect in particular is still impressive because it's deceptively simple and doesn't rely on gadgetry:
How can we forget Kermit the Frog riding a bicycle? How did he--or, rather, Muppeteer-in-Chief Jim Henson and special effects supervisor Robbie Knott--achieve the feat?
Well, they started by making a scaled-down model of a Schwinn cruiser. Now, I don't know whether an actual frog can ride a bicycle, but I don't think a puppet can. So, for the bike-riding scene, Henson and Knott, in essence, turned Kermit into a marionette.
The full-bodied Kermit puppet was posed on the miniature bicycle, hands on the bars, feet on the pedals. Then invisible wires were attached to him, which allowed Knott to maneuver him from a crane hidden from the camera's view. For close-ups, Henson used a hand puppet of Kermit, which he operated below the camera while riding a low-rolling dolley.
Henson and Knott undoubtedly would agree with Kermit: It isn't easy bein' green!
