I have invested there and played also, they have only a small money pot, so if you area planning to invest big then you will have a good profit. In addition, this site is operating for more that a year already, I believe they are trusted.
You shouldn't forget that CLAM are a staking coin and you could make a decent profit (in terms of clams, maybe not in terms of btc equivalent) by staking them yourself/in a pool without any gambling aspect behind it.