Reddit user fab1anfab1an started a game of sorts where clues are given that lead to the eventual discovery of a wallet's private key with its contents up for grabs. Discussion occurs on Reddit. Yesterday, the 8th one went live and while it was solved by two people, they both left some for the next person. While lower than the initial 0.2 BTC reward, there is still roughly 23 mBTC left if someone wants to have some fun solving a series of clues and riddles.
The main site is
bitcoinriddle.com (developed by fab1anfab1an on reddit).
Here is the thread to the most recent one ( number 8 ) which links you to the riddle page as well as serves as the platform for some additional discussion and hints (e.g. Hint number 10). I figured some folks here might find it fun.