Wow! You and your friends thought up some pretty interesting gameplay. I never would have come up with that. If your primary concern is conserving your balance and gradually working up that balance, then select low or medium variance slots with an RTP 96% or higher. Those fast-paced high variance games will drain all of your free daily bonus fast you'll need a huge stockpile of gold coins for those. Take a look at the sweepstakes casino lobby right here on the Yay page. Personally, I would try 40 Super Clover or Double Joker Fever. To last the long hours of playing, play games with frequent small payments and free spin sessions. I'm curious what gameplay strategy led your friends to grow their gold coin reserve so quickly?