First off, I really enjoy the game. It's fun and cosmetically good.
I could see myself spending a lot of time playing and enjoying it.
My only major problem: the energy system.
Though it is a nice tool to make it so that people don't kill themselves playing for 48 hours straight, it REALLY limits playtime and detracts from the game experience.
For example...
I can play for a while, spend all of my energy, and then suddenly have a friend ask to play with me. Why would I say no? I want to play with him after all. But, I don't have any energy left.
So at that point, my friend has to pay for me AND himself as well. It definitely doesn't make me feel good to know that I'm draining away my friend's energy, and it makes the game a lot less enjoyable for me.
You might suggest buying energy crystals, but I really don't have any money to be able to spend on the game, even on micro-transactions.
I'm just a teenager, so I don't have a credit cart to buy energy with. And I'm not about to go bug my family to buy it for me.
My suggestion is to add an energy reward for completing a dungeon.
That way, if you spend energy doing your own thing, you'll get a bonus when you finish that'll let you play with your friends or do other activities.
It also makes the above situation a lot less annoying because we'd both get energy back.
You can buy energy off the exchange with crowns.