I think so, actually. When I start implementation, I'll probably use an Interactive Fiction engine as another person on this thread suggested, because (a) it makes implementation a lot easier and (b) I've enjoyed a lot of IF but I haven't ever made one of my own. That would imply removing a fair amount of the RPG-ness in your original suggestion, but the basic ideas would still stand. I'm also considering changing the setting to make it an alien world which just happens to be very much like 17th century England except filled with humorous Rubber Forehead Aliens; maybe the game could be called Standing On The Eyestalks Of Giants.
On the particular criteria:
Interesting: I think the setting and the (hopefully generated) buzz would build enough initial interest to carry the player through the first frustrating parts where things don't seem to work as they are used to. Once they get the idea that they're playing as something like an alien Newton, that ought to push up the interest curve again a fair amount.
Not (too) allegorical: Everybody loves making fun of alchemists. Now that I think of it, though, maybe I want to make sure the game is still allegorical enough to modern-day issues so that it doesn't encourage hindsight bias.
Dramatic/Surprising: IF has some advantages here in that there's an expectation already in place that effects will be described with sentences instead of raw HP numbers and the like. It should be possible to hit the balance where being rational and figuring things out gets the player significant benefits (Dramatic) , but the broken theories being used by the alien alchemists and astrologists are convincing enough to fool the player at first into thinking certain issues are non-puzzles (Surprising).
Not rigged: Assuming the interface for modelling the game world's physics and doing experiments is sophisticated enough, this should prevent the feeling that the player can win by just finding the button marked "I Am Rational" and hitting it. However, I think this is the trickiest part programming-wise.
I'm going to look into IF programming a bit to figure out how implementable some of this stuff is. I won't and can't make promises regarding timescale or even completability, however: I have several other projects going right now which have to take priority.
Let me know if you would like help with the writing, either in terms of brainstorming, mapping the flow, or even just copyediting.
This thread is for the discussion of Less Wrong topics that have not appeared in recent posts. If a discussion gets unwieldy, celebrate by turning it into a top-level post.