dear admin I thing the mining expiry time is too fast and need to spend all collect coins on upgrading the miners and at the end we will loose it
I agree on this. What is the use of spending coins for miners when all the income is lost for maintaining their health?
Sure, it doesn't make sense, having to buy energy all the time in order to collect.
Energy should be earned through some work, shortlinks, offerwalls or else.
The lottery is good.