Chinese people are business minded, they did not put anythings that might give them risks. And in your case, your negotiation between Chinese buyer seems like unfair. Imagine, he will receive the game after his payment. He always aware of scammers, and it is possible that he will think that you are scammer too but it is not! Please try to contact him in real world or have an escrow wherein the two of you will transact easily and reliable.
It sounds fair if the seller has reputation over him, if not, then one of the sides would need to prove reputation to the other side, and if the other side will feel that it is not enoughthen you will probably need to use an escrow because the deal will not go through.
If one of the sides refused to usr a verified escrow service, then there is a reason to think that he was attempting a fraud.
Take all the caution needed while doing peer to peer trades.