I do acknowledge your concerns. It's tough in this space to build up reputation.
We've come up with a way to alleviate those concerns a little. We're giving away 10k satoshi for betting (withdrawing not possible) per unique user for the time being, twitter is being used to verify that it's a unique user and it's also a good way of building up a community for our future projects and plans. HalvingGame is supposed to be just the first one of its kind.
Those who mistrust us can just take advantage of that bonus while we build up reputation. At halving day, we'll deposit all those bonuses into the hot wallet to allow the winners to withdraw. No need to trust us for this.