I'm working on a fun project that uses 39dll.
If anyone else knows what the hell that is, PM me.
There was or is a certain game called Dragon's Tale which was essentially a casino disguised as an rpg.
You had bitcoins, and every action you did was a bet to a certain extent.
I don't know if they still exist, though.
Then there's technically the former BitVegas.net etc., people who took one game and put bitcoin into it themselves.