Fun but super slow going without spending $ or gems. The energy you have and need to use are vastly far apart. I.e., clearing away a pile of rocks can take 1/4 to all of your energy depending on the size. You spend so much energy and time to upgrade your house for only 1 additional energy to your total energy! Then you have the competitions and that takes your energy instead of trying to upgrade your own island (so you have to choose your battles).