Whoops, yeah, you probably shouldn't have given away the twist there. But by the time you finish the story people may have forgotten about this thread.
I'm not sure more than a couple of people got to see what you had before you unpublished it, you can post a link here for a better way to give people an idea of your writing style. Besides that, I'd suggest taking what you have and pasting it over into a fresh story. Once you're finished, that one won't show up on the main stories page since you published it already.
And of course, planning is everything. If the player always winds up at that 'dramatic reveal' it'll take some work to get them there while still making sure they don't feel like they're being railroaded.