It's sad to see the mining game gone. Spent a lot of time playing it.
But I have always wondered about the economical sustainability of that game.
On one hand I want to waiver my payout but on the other hand I've spent a lot of time and coins on it.
Me too. It was too good to be true. They had to know that 60 gems per coin ratio was too much at the beginning. They had to know that game was struggling when they introduced 5% interest only 12 days before end of game, still they introduced it. In chat they said that they have sustainability at least 3 years, but it was a lie. Probably good money for devs, but thousands worked for nothing many months.