yeah the theme itself is unfair >< gambling without real monney takes most of the tension away so its tricky to makes something that is both fun and fair, its why i ended up giving the possibility in my game to modify many options until you find a satisfying difficulty level.
But balancing games is hell.
That being said, your game is really good and just lack some balancing and couple additions here and there and you have a complete game in my opinion :)