I'm not aware of anyone giving bitcoin just for playing. Why would they do that? Maybe there is a reason?
For me, this is for fun and plus get benefit from my hobby.
Most of the projects I have seen to include BTC in games are focused on sales of virtual items or prize money for competitions. For example let's say you are about to play a deathmatch with some friends. Each confident player could put up some funds and the winner takes all at the end.
Most all of BTC games is the same, that's the rules.