Springheel

Good luck. These standalone efforts are really popular. I guess it's hard to estimate how much objection people have to buying the base game when you already own it...

That seems like it would be a tough thing to do. (from my limited understanding) You would have to re-create or edit all of the head skins as well so they properly "wrap" around the new head model, right?

There actually aren't very many skins involved. Most heads have just one texture. Replacing heads isn't as difficult as characters like the zombie.