This is a refreshing twist on card game mechanics. Along with basically having every topic imaginable, you're able to play any card any way you want. The backs of cards are very cool with the information and it's surprisingly easy to build up a library of good cards. For a free game, the ads are not intrusive and as far as I can tell, you won't ever see any unless you want some bonuses, so they're basically non existent. Kudos to the creators, this is a fantastic game if you're into cards.