I noticed that gems are essential to the game. how can it be acquired aside from buying it?
Check this wikia where you can get all the info by searching what you want http://royal-revolt-2.wikia.com/wiki/Royal_Revolt_2_Wiki
Here Gems: http://royal-revolt-2.wikia.com/wiki/Gems
Here Flothaboss video on how to get gems: https://www.youtube.com/watch?v=gVwO4-CrDPs
If you are on an Android or iPhone, you can watch adds or sign up for offers through their TAPJOY add system and get free food and gems.