Some friendly advice
1. Cool design. Should make it responsive too.
2. Seriously? Yet another dice game? btcdice/royalbitcoins/nakabot/I lost count. Please do something original. And by original, I mean something like BTCKeno or that bitcoin RPS game, not another video poker or blackjack.
3. Why would a player want to contribute to the lottery pot if he's playing dice, and has no chance to win the pot?
Okay, actual advice now:
4. You shouldn't call "x2" when it's actually "x1.976". Instead, make it pay out two times, and just adjust the odds to 49.4% or something.
5. Have some sucker 97% / 80% / etc dice tiers. Why? Well, let's say you have 1.92 BTC and you want to buy that bitmit item for 2 BTC.
6. Most important one. DON'T ACCEPT 0 CONFIRM, 0 FEE TXes UNLESS ALL THE INPUTS ARE CONFIRMED. And the one TX per minute isn't well thought out, like what Stephen said.