RollerCoin is one of the best free mining games to earn Bitcoins: play and earn mining power to mine BTCs and earn satoshis. Rollercoin (official website) is a free simulation game, where by playing alone or with your friends you actually make some money.
RollerCoin will not make you rich but in long run, you may be able to make extra income from it if you are committed to it, last I check the leaderboard, the person on top played for 18months, and is estimated to be earning around $1500 worth of crypto a month!
link : rollercoin
https://rollercoin.com/?r=ky46o0ya
https://rollercoin.com/?r=ky46o0ya
