Trying this out, I can say that its extremely difficult, perhaps too difficult.
A coin flip game is ridiculous for this style of game, with a 15 wager it takes too long to reduce to 0. The main lobby is tedius but otherwise easy.
Ma'riska took extremely long to get a single clear, as there is no indication of where the enemies come from, thus making an instant loss the more common scenario. Every mini-game takes too long to complete effeciently, and I think a stronger payout is necessary.
Ravenna was the most fun out of all of them, as she could be challenging for risk, or full combat and take longer. This was done well.
Tenevore was... eh. Blackjack is always hit and miss, just as bad as the coinflip, but you can't exactly make it easier. I just think once again, allow a higher wager for confident players.