Aside from the very simple design which is not attractive, there is also a big missing thing in this site. It is about the provably fair system, I cant find anything related to how the coinflip works which should be the most important thing in this kind of game. Without provably fair system, there is a high chance for cheating attempt.
The available games to be joined seems to be made by the admin to attract users but it wont work. I believe no one will spend their money on a non provably fair coinflip game.
One more thing, fee for instant withdrawal is so high (1000bits = 100k satoshi).