It seems like he was scamming. I doubt Poloniex had anything to do with it other than being a scapegoat.
The Crypto-Kingdom game founded and run by rpietila (forum profile
link) started as a legitimate fantasy role playing game with a rich economic model and an in-game currency fully-backed by real crypto (XMR).
However, it was recently turned into a fraudulent fractional reserve scam when rpietila decided to create in-game tokens for himself without depositing, and further being unwilling or unable to pay the resulting debts incurred by the game and himself.