I'm going to link myself today. Some years ago, I ported the roguelike Omega to Windows. Today, I packaged up the source code (someone finally asked); link here:

http://www.prankster.com/winomega/index.htm

Omega is a roguelike game which started a few years after the genre-defining games NetHack and Moria (later Angband). Omega features exploration, with a countryside map, whereas in most roguelikes the path is pretty well defined (down the next set of stairs). In addition, character development in Omega is partly driven through interaction with the world, not just a matter of gaining experience and levels. (I've heard people refer to this as "plot", though that might be a bit of a misnomer). I don't have any direct evidence, but I suspect the design of Omega was influenced by the Ultima games (maybe Ultima III?), merging that with roguelike sensibilities.



From a game design perspective, on the one hand, Omega is very compelling. The exploration aspect is very well done; there are many interesting locations to visit and discover, all with their own unique identities and rewards. The impression you get of influencing the world is wonderful; for instance, all of the guilds have their own Head (the Duke of Rampart, for instance), but if you progress far enough, _you_ become the Head of the guild. Now, if you look pragmatically, not that much changes in the world when you do ascend to that position. For me, at least, these features give the illusion of a deep and fully-realized world that is often lacking in even large commercial games.

In addition I should note that Omega hasn't undergone active development in quite some time, and was never that popular, so it has suffered in comparison to more popular roguelikes. The inventory system is byzantine, and now-standard features like line of sight, or intelligent running, are absent. Monster memory? What do you think notepad is for? So, if you're looking for a great, polished game to play, Omega might not be for you.

Ultimately, I would categorize Omega as a fascinating failure. The design of exploration, both of the world and the game system, is really interesting. Unfortunately, paired with the permanent-death style of roguelikes, makes for a frustrating playing experience; you hear people complain about insta-deaths in Omega, and for a good reason. There are (almost) always good ways to avoid the insta-deaths, but unfortunately the way to avoid them requires many hours of play, many deaths (even of high-level characters), and deciphering cryptic hints. (Or heavy reference to the spoilers, which, to be honest, is probably a necessity to play). As an example, being put to sleep by a monster is almost always fatal. However, there is an easy way to become permanently immune to sleep; eat a szechuan pepper. Good luck figuring this out without spoilers!

I would contrast this with the exploration-heavy game Ultima IV, which in a lot of ways has a less compelling exploration mechanic; there are many interesting locations, but the aspect of affecting the world is much less in U4 than in Omega. However, the insta-death problem is absent in U4, and even if you die the game very forgivingly brings you back to life with only minor penalties. As such, Ultima IV is a much more satisfying experience for all but the most challenge-driven players.