Love the concept! My biggest suggestion would be to move the controls from the arrows to "AWSD" and then make the user only use the wasd controls, spacebar and mouse, as moving from the arrows to the mouse is quite daunting! Or, at least, provide both options to the player :D
I would also suggest for you to make both UIs (betting and skills upgrade) to be both either mouse controlled or be keyboard controlled, as changing between the two, from the experience of a new user, can be quite confusing! Either that or I'm getting older xD