It's not that hard as you think right now :) The Problem is more in wine's source code that implements the API, we are implementing a big portion of the really needed API, but of course there are Bugs and some APIs are just not implemented. recently code got in to use a X feature called xinput2 to get better mouse input, that caused bugs in some games, but made much others happy. now we only need to fix "some" games :)
