this whole thing just reeks of wrong to me. Not provably fair, nothing too tiny about those pay-in's either. I've got to say I think this needs to go back to the drawing board, I'd be inclined to dial down both the buy in and pay outs. I think you're going for a 'fun-time-bit-of-a-flutter' type users here not pitching yourself up against those more serious 'seals with clubs' types.
just my two satoshi here

Hi, thank you for your feedback. I'd have to say it actually is provably fair, since all transactions and payouts are disclosed as soon as the pot threshold is reached/paid out, and if anyone who paid in saw their transaction missing from the list after the payout then it would be 'provably unfair'. The minimum pay-in is .01 BTC which is currently around $8, it's not pennies but it's far from a large amount IMO, especially when the payout is $80. Also, .01 BTC is the minimum payment at that level on Coinbase, which is why that value was selected.