I like the concept of Battle Field a lot, at least for casual play. I have one idea though. What if the battle fields actually were predetermined for both players and activated every time a rescue attempt was made (that way it's like your fighting at different sites every battle)? It would go some thing like this:
You start the game with a pile of lets say 8 battlefield cards that you have predetermined. These do not count towards deck building rules. When your opponent attacks you you may select one to flip up and it immediately activates (so it's like your fighting there) and is discarded at the end of turn. The battle field would have to be defensively slanted like Polarius' cards for this version to work but I guess in theory you could have both in your pile and say the person with the least lost souls chooses.
Now I see this getting out of control really fast (my version) so I think it would be even better if you made then really funny and wierd, or maybe even have a central pile and randomize it. You could have some thing like all character names that begin with the letter "L" must return to territory or search deck for a card that Rhymes with A Bew Neginning or Que maybe be redeemed. Add some pretty silly decks like back ground, or just all some crazy troll ones. Cactus wouldn't need to print anything or sponsor it even. We could call it type Troll or Type B heh. It would be more like a fun game you play with your family on friday night than a ccg but it might call for some epic times at nationals. Sort of reminds me of a redemption version of apples to apples or flux. Every body builds a funny deck and comes with funny battlefields that they made and competes for a prize. You could even do deck swap with it.
In summary (that was sort of a mind dump)
1) Make some funny battlefield cards
2) Make a fun deck
3) Troll
I just thought of this idea because I like LoTR CCG, its like the site path and fun troll games. For more serious stuff and tournament play
Polarius.