This basically sounds like, and probably has been, the premise of an old Marvel What If… comic. Why play as Spidey in the upcoming The Amazing Spider-Man game when you can play as Stan "The Man" Lee himself? That's precisely what pre-ordering through Amazon will let you do.
The Stan Lee Adventure Pack includes a mission that has Lee swinging through New York City just like Spider-Man. Fully voiced by the man himself, Stan Lee has somehow been blessed with the webhead's ability to wall crawl, web rush, and swing with his webbing. His mission: Collect missing pages of his latest script, naturally. I imagine this is something that happens to Stan Lee on a regular basis.
That's not the only pre-order bonus in town for The Amazing Spider-Man. Pre-order through GameStop and you'll get a different pack featuring The Rhino Challenge. This one lets you play as Rhino, racking up points as you cause damage in a rampage throughout NYC.
Personally, I'd opt for the Stan Lee pack just for the sheer ridiculousness of it. WHAT IF... This Game is Actually Good?