Love it! Great concept. Looks intimidating and overwhelming at first, but I like the way it's not about mathematically subtracting from a few million to zero at all. It's about waiting for the better cards in the later rounds to 'cheat' the individual digits to zero. I played it 4 times, and opened the safe on all of those occasions.
My main criticism is that the background 'music' (ambience?) is painful. It definitely give an edge of suspense and tension, but it's just too painful for me. The other sounds and the rest of the presentation are excellent though.
Minor criticisms include the overpowered "Set all odd to 0" and its "even" counterpart. I once got both in the same run, that is the ultimate easy mode! Also, I'm not sure if there's a minor resetting bug. It seemed on my first run to pick low quality cards that made it look like an impossible task. Then in subsequent runs I'd start with some of the more powerful cards in my hand. Maybe the shuffle isn't doing quite what it's supposed to?
Anyway, a little balancing and I'd play this game as a Daily Puzzle for sure!