First, the TL;DR:
Side-scrolling Castlevania, roguelike random room placement. Good idea, or bad?
And now...the treatise.

Maria:
It's strange. This castle is different then I remember it.Alucard:
This castle is a creature of chaos. It may take many incarnations.Maria:
I can't trust my memories huh? Oh well, I'll do my best.This conversation highlighted the differences between Rondo of Blood and its direct sequel, Symphony of the Night. If one were to play them back to back, there would be areas like the clock tower that strike that similar-but-different vibe. But of course, this is a comparison of two different games, and each game's own design remains static.
But suppose the design WASN'T static? Suppose, as a "creature of chaos", the game layout changed each time you played?
That has been the major design of the "roguelike" games. The plots are generally simple: descend into a dungeon, kill the bad guy, come back. But to make it interesting, each visit to the dungeon is randomized, using templates of rooms and connecting halls. So while the feel of the game remains the same, the ever-changing layout keeps the players off-guard. And thus, even in ascii or low-res graphics, these games remain highly popular. In fact, there IS a top-down Castlevania roguelike out there!
However, that's top-down. Can such a feel be caught in the traditional SIDE-SCROLLING Castlevania style?
Consider, for example, a Marble Gallery. First time you play the game, it flows from left to right in a generally straight line. The SECOND time, however, it goes from right to left...mostly. Seems that there's quite a lot more vertically-oriented rooms this time, which kinda throws things off a bit. Or how about, in true RL fashion, it puts you in the "MIDDLE" of the level, and now you have to decide which way to go!
(And if this game has editor tools, like what the Diablo-inspired Torchlight has done for its fans, imagine what crazy fan-designed templates can spice up the mix!)
So there you have it. Now, there are two questions:
1. Could such a thing be done relatively easily, or is it a nightmare in the making?
2. If it COULD be done, would anyone want to PLAY it?
p.s. I even have a name in mind:
Castlevania: Scherzo of Chaos

p.p.s. However, since I can't code my way out of a paper bag, I'd have to leave this idea to someone who wouldn't make it suck.
