Ooh, have you decided on a language yet? The latest stuff I've been working on is in Python, the previous one was C++ and prior to that, Spidermonkey Javascript. They're technically all similar, but it's still fun learning new ones.
My suggestions:
* Don't be afraid to do something different with this. I just played a Roguelike that plays in psuedo real-time (think Baldur's Gate); it worked quite well. That's just an example. There was still strategy, but the tension and "oh no, I'm losing!" was amplified.
* Avoid making the player grind for anything, but don't *force* them to keep moving. I liked Dungeon Crawl, but the game was designed to force you to keep moving forward. It's fun, but I like being able to do what I want to do, even if what I want to do is boring. I doubt that will be a problem with a concept like this, but I thought I'd mention it anyway.
* Possibly look into a customized character set. ASCII is great; I love ASCII. Even Toady mentioned, however, the stress the letter "E" was receiving. If you make it ASCII, consider having custom characters that resemble letters and symbols. Incursion had tiny smileys for halflings, thin smileys with long ears for Elves, and a few other little additions. You can maintain the style and ease of use while still going beyond the usual boundaries.
I can't think of anything else relevant. Good luck, though! Show how awesome the community is.