My issue when watching it the first time was that I didn't understand what actually made the situation so dangerous, when it being dangerous was clearly part of the intent. After all, they
did fall before making it all the way down, and all that happened was exactly what it seemed like would - they landed in some shallow water. The stone spikes were so sparse that they were more like decoration rather than a threat. And that effectively destroys any suspense/excitement the scene might have theoretically generated.
I realize that the scene is, design-wise, fundamentally different from something like the spike scene in Temple of Doom in that the objective is to Run As Fast As You Can rather than Find the Lever, but I still feel that the spike room is useful as a comparison because it shows you what this scene is lacking - clear danger. Even if time doesn't seem to pass consistently in Temple's scene (how many times do the spikes seem to be "almost" getting Indy and Shorty from the same ceiling height?), the key to what makes it work is that we understand what the solution is: Willie getting to the lever before Indy and Shorty get skewered. We're into the scene because we're given the solution
before, and not after, the problem is solved. Again, this has nothing to do with the fact that the staircase sequence is intended to be more of a smaller, sudden type of scene. That's not an excuse for confusion.
How would I have changed the staircase, scene, then? I guess I would simply have made it so that the consequences of the heroes not getting to the bottom (or close enough) was more obvious. Maybe make it so that the retracting stairs lead directly to an entrance, with there being a bottomless pit instead of a floor. Or, make the floor
entirely made of spikes so that we
know that if they fall, they're screwed. Then when they do fall you can have Marion or somebody grab a stone extension for support which turns out to be the release lever or something. (That does
not change the purpose of the scene from "Outrun the steps" to "Find the lever!") As it is in the movie there's no last minute escape/save because I wasn't sure if there was anything they had to escape from! I mean, okay, if you want to pretend these movies are photorealistic you could easily argue that falling from any height greater than they did would have potentially caused broken bones, but I think we can all agree that if "they would have broken their bones" is offered as a justification for something in an Indiana Jones movie, that person has gone off the deep end. Spikes, bottomless pits, pool of sharks, vat of lava, etc. are what's called for in a pulp adventure, not a freaking puddle.
By the way, I don't think my earlier complaint about the cost of the set is unfair, because the original trilogy was made with intentionally low budgets, with the sets and props being used to their fullest potential, because they had to be. They had to go through actual trouble to get that Nazi plane in Raiders, and Spielberg milked it for all it was worth with the Pat Roach fistfight - no machine gun, cement triangles, or propeller went unused, because Spielberg used that toy in every way a little kid might with a model plane. Kingdom of the Crystal Skull had a much bigger budget than the previous movies, and I do believe that holds true with inflation adjusted. (It is also, I believe, the first movie that wasn't finished under budget.) This movie has some of the most impressive sets in the whole series. So yes, I will be critical when I see a giant pyramid complete with a hundred armed Indian extras used for a perfunctory and wasted "action sequence," when you know damn well that in the 80s such expenses would have been the first thing Lucas would have cut from the budget if nothing creative or meaty was going to be done with it. Same goes with fully functional jungle cutters, giant obelisks that actually come together in an elaborate practical effect, and real retracting staircases built to scale. The production values in this movie are higher than the material deserves. Yes, the retracting staircase does
work, if that's what your bar is, and it is not some horrible scene that I would ever cite as some gigantic failing that sinks the movie. It is, however, extremely representative of a problem that the movie suffers from in general, and it does contribute to a quality that I think separate Indy4 in spirit (rather than era, age, or special effects) from the other films.