I was thinking about this earlier. The card game bit really. Many people try to force games like Zelda into card games, and the fits aren't really that natural. (I know, you're not trying to create a Zelda one, but Mario is an odd choice too.) The series that I think is perfect for it already has Land attributes, attack/defense ratings, strengths/defense against X, and abilities for cards.
Nintendo Wars does all that. I can see it being played similar to Magic-The Gathering, with people building a specific deck for Naval, Aerial, Ground combat; having terrain cards such as Mountains which provide defense boosts, but can only be used by foot soldiers. Having to "tap" a certain number of say Air (terrain) cards to employ a Battle Chopper. Substitute "Gas" for a number of lands needing to be tapped to play the card, and so on
CO powers as ability cards. Or even special cards such as a ship being blocked by a hidden submarine. Fog of War- players turn their cards face down and can rearrange them so the attacker wouldn't know what was being attacked until after deciding which card to attack. etc.
It could work out so well.
Plus, repeating characters in a deck is odd, so several Links/Marios, etc would need some explaining. Wars repeats the units anyway so the fit is even more ideal.
