Some interesting concepts here. The "Sacrifice" mechanic is pretty interesting and fun to use in its own right. However, the method to win the main game is incredibly straightforward (I really don't get what the other commenter means about being able to employ strategy): Max out luck, and then keep buying cards over and over. Once you're pulling the dragon, unicorn, and griffin each time, you will be staring at the card opening screens far more than the actual card battles. It's also very annoying having the enter an action 3 times to open the card packs and turns an incremental autobattler into a button masher.
Leaves something to be desired in terms of gameplay.