How to Procure Unlimited Energy for Free
On mobile device, set the date & time settings to a day ahead.
Check whether your energy bar is full when you open Deer Hunter.
Re-set the clock and then set it to the right time.
As a result, you will have a full energy bar when you re-open Deer Hunter.
Do this as frequently as you need for free unlimited energy when playing Deer
Hunter. The same procedure applies for imported upgrades. There is no need to
wait long periods anymore.