I think this could be a cool idea, but I think you're likely going to end up crossing over into creating a codebase instead of a framework. For example, how will you provide any kind of generic structure for facilitating the creation of an arbitrary movement system?
This was a silly idea not too many years ago, but nowadays, it's trivial to set up a new linux virtual machine, and making a custom linux distro that's specifically designed to do a single thing is also not absurd. Onlly bummer is, the name MudOS is already taken. *grin*
I just wrote your project for you.