It's a very fun game, and not a bad implementation. Right now, though, it's bug city. The "new game" function essentially doesn't work, because if you use it your next game will bug in a way that makes it unwinable.
Issues (on Safari, OSX)
1. After starting a new game, unused diamonds frequently refuse to attack cards, especially aces. Occasionally, a diamond will attack, but the monster card will not disappear; the diamond then refuses to attack going forward.
2. There appears to be an "off-by-one" error in the win-condition, as I always win with one card left, sometimes a card that would kill me.
3. The "room" cards are almost exactly four card-lengths to the right of where they should be.