No extra features? How about two new weather conditions, a new type, about half of the new moves have unique effects and don't get me started on abilities which may or may not (ability dependant) have to be referenced in EVERYTHING they might affect. Unless you got a well coordinated team it's just not feasible to have group coding. I mean sure, it *can* be done in a group, but it can only be programmed by one person at a time as far as I can tell.
And that reminds me, I still have to figure out where we are on abilities (and to get someone to do Sacrifice).