Overall, it's a simple design - that's not a knock. Many people try to overcomplicate their designs. Yours is more of a magician's deck. I know a few collectors that will be tired of seeing yet another deck with skulls in the design, but I'm partial to them myself, especially when they're well done.
My two beefs:
1) the tuck box doesn't look as nice with the wraparound title like that. No one will see the full title without tearing open their boxes. I think you could have done better with the box art - and there are segments of the collector market that purchase their decks almost exclusively based on how attractive the tuck box art is.
2) $13 a pack is a little pricy for an MPC deck. They're decent, but they're not that good to be worth that premium a price. The quality's not as high as with some other manufacturers - better than many, sure, but not top-tier. You could have aimed for a lower goal and a shorter print run with a lower per-deck price and improved your chances for success. If your project doesn't hit the goal, consider retooling it in terms of print run size and price point.
Best of luck to you!