It's a great beta, I really like the art style. I know this is still in development and many features will be later added but I would like to share my personal opinion:
1.It needs more feedback & sounds for when the player or the "Dealer" make a move.
2.I think it would be very nice if you could add mid-combat dialogues. So the player could learn more about the intentions of the "Dealer" (It would also make it a lot more distinguishable from buckshot roulette)
3.A few animations would be a nice touch too. I have no idea how hard implementing animations in RPG Maker would be, but I'm sure that it will make battles much more intense & immersive.
I know you have probably thought about implementing these features before I mentioned them, but it is still a good reminder.
Anyways, good luck!