Hi @darkpylon, the tickbox is there for you to confirm that the game is your own work, and that you have placed your username, i.e. "@darkpylon", somewhere visible in the game. This is a requirement of your game before it will be accepted by the auditors.

As for your other question about commanding the player's account to create a post, we are working on a SDK that allows developer to more easily incorporate STEEM features into their games. Hopefully we will have something by end of Q1 2019.