There is one improvement you can make on your betting site. In each of the games, in the box you're supposed to enter your betting amount into, when you click on this box the entire number is selected and anything you type will erase the box contents with your number. This makes it take longer to type fractional BTC values. In time-sensitive games e.g. Crash, being able to change your bet quickly is very important, any not everyone uses a strategy that doubles or halves their bet (the two buttons next to the text box).

So I suggest that instead of selecting the entire box content to be erased, make it so that users can select the part of the text they want to edit and change the digits of the BTC balance that they want to alter. This can easily be done with some CSS.