Bug: I returned to the game and the double or nothing got knocked back two levels (I still have most of the quests done, currently showing I am on Risk it all 5) BUT there is also a risk it all 1 in the quest list now too.
Suggestion: Add roulette to casino or maybe some player vs dealer games instead of just like you are playing against yourself. Add some opportunities in the banking area such as investing (% chance to succeed you get a #x return). Add another interactive game that rewards you based on skill (like a avoid the wall game that you get a $ return on how far you get; this could be applied to the whack a seal game as well)
All in all, entertaining game -- keep up the good work. A little slow for an idle game, but hey it's idle so eventually I'll have enough :P