Nice concept. I recommend the addition of a deck builder which can mix cards from both players to create on board. You can even create some unique slots for some cards, so a card at the same place on board will have an effect for a player and other effect for another.
Awesome game. It has an excellent gameplay; regular but funny history; plenty of abilities and weapons with a good upgrade system.
The biggest flaw are the weapons and items: they are poorly balanced; doesn't cover all gaps and you probably doesn't want to use the same set.