I had this idea a few years ago
http://www.oddworldforums.net/showthread.php?t=18528
And some animations running with a cam/background:
https://www.youtube.com/watch?v=kdhI...136P7aCnT-uvzQ
I would recommend you use C++ rather than C#, C++ can be ported to almost anything. Any indie game such as The Swapper which used C# always ends up getting ported to C++ for other platforms.
LUA seems to be the defacto scripting language to use these days too.
Edit: Also!
You should really consider writing the engine tools before the engine itself. Its not very flexible to have some text files to setup animations and such. You need an object editor which lets you preview animations, setup animation transitions and set up AI scripts for that object etc.
It would be a huge task to get this working properly
You'd really need to think about the design first.
.. and of course a full blown level editor so people can actually create content with their new objects or edited existing objects.
Then you could think about a basic engine just to display the content from this - if its a new engine you'd want a way to dynamically reload the content on the fly. Then you could get into the harder things like making the AI work and getting the game play correct. Don't forget you'd need a "real" sound engine too.
Edit again:
And not to sound too negative - I think this is a good idea (hence why I suggested this a long time ago
). But LUA/C++/SDL or SFML would be much better than using C# frameworks.
A proper design would be the first step though - then you could get a mercurial repo up on bitbucket or something.