testing the demo mode, the choice of colour combination for me is not really good for the eyes, even if you go blue or go black. or is it just me?
 also, am wondering if someone wins big, do you guarantee that you have the bankroll to pay that player?  just to get an assurance from your side here.
and as others have suggested, if you can separate the demo players and the real players, that would be better, i guess.