Don't know why I've skipped posting this here before. This is a semi-commercial project, but it may be of interest to some.
Through my company, I've been slowly developing a set of game engine technologies that pretty much have a foot in most of the common game types - the idea ultimately being that
EGene, the overall name of the project, will allow the different types of game to merge into each other during game play. e.g. Think of an Elite style game using 3D, switching to a orthographic scroller for local movement, switching to a text-based adventure engine for puzzles and interaction at a personal level, and you get the idea. We think that the FPS style is being done-to-death at the moment, so that type of thing is low on our priority list, but we'll get there.
Work is well under way for several of the different stages, one of which has already been released as a stand-along game engine - principally because of some side-benefits that it provides in literacy - the overview of TBag (Text-Based Adventure Game engine) can be see
here. Screenshots really show TBag's implementation in a simple front-end for release - the power of the TBag stage actually lies in the underlying classes.
I can't say much more about the other elements of EGene that are in the works, but next steps for TBag at least are completing some multi-user features (including multiple TBag games talking to each other across the network) and adding some psuedo-AI features allowing character interaction. At least one major TBag adventure in the works (all of which are fed from an XML file) involves Q&A style interrogation, so its a major feature requirement.
Probably the next stage release (non-TBag) will be the orthographic game engine - also fed from an XML file.