Cards?

I've been obsessed with the concept of cards as a collectible resource within a game. It's a neat aspect of a little strategy game I've been playing (strangely very similar to own of my own) called 'State of War' where all resources are cards - be it wood, ore, gold, clay etc. Some actions cost simply any card, which can be any of those listed.

Being an avid CCG gamer and collector, the idea appeals to me greatly. How can I expand on this simple but effective concept of cards within a game that isn't wholly a card game? Collecting in itself is an appealing past time and from my experience the accumulation of things in a game can be objective enough for some people to play it regardless of other facets.

I return to my ideas of a top-down role-play game. Put yourself in control of a character exploring a fantasy world, collecting items as you discover places and overcome obstacles or enemies. Now, if these items that you acquired were cards, you could both have a running objective (accumulation of cards) and a resource for comparison, achievement and heck, bragging rights!

If you can imagine the classic Zelda (pictured), you controlled a character central to the screen, viewing the world from above and moved around the environment. This is where my mind is heading...