It's a time consuming game that was pretty fun until I spent 250 gems on professors switch system. During the day the regeneration speed did get faster but when I switched to nighttime it didn't regenerate energy at all. It said my max was 200 energy when right now my max is close to 3500. I'm pretty unhappy about it because it took me a long time to accumulate 250 gems to purchase it. I had thought it was supposed to regenerate energy all through the night when I flipped the switch.