For the sake of people looking at your cards, make the background SIMPLE. A wood table, green felt, etc. Your design is too distracting and makes it harder to focus on the real reason for being there - the cards.
The indices are slim to be point of nearly invisible. Beef them up a little.
REMOVE the extra pip in the center of the spot cards. You'll only create confusion for people who play with it - it's enough to make people not want to buy it, trust me.
Remove the shadowing effect you have on all the cards. They're flat pieces of pasteboard, not shadow boxes, and it that's actually part of the printed pattern, lose it - it makes your deck one-way when you're apparently trying to make it two-way.
The linework in the courts, like the indices, is thin to the point of practically invisible. Against a busy background like that it'll be hard to distinguish.
Speaking of the card background - why? It really is busy and detracts from rather than adds to the artwork presented on it. It's like looking for broken glass in a tub of ice - the artwork vanishes in the camouflage of the background. Simple is often better - try simplifying the background to all black or (even better) all deep gray. You WANT people to see your art, it's the deck's primary selling point, so don't disguise it so much.
