Yeah, there could definitely be more characters, that's for sure, but I'd say just wait for the more complete installment and package of this game. Especially considering the DLC option in the game, this is definitely not the final product.
EDIT: And there's three open character slots that were found in the game which means that there are definitely more characters coming.
EDIT: And there's three open character slots that were found in the game which means that there are definitely more characters coming.