1. Game is very expensive!! Events cannot be completed without spending lots of money. You need money to buy gems which are required to buy buildings. Some of the actions such as early upgrade could cost as much as hundreds of dollars. Yup, no typo there. Hundreds.
2. Game is full of bugs. Game currently cannot be played with ios 9. Game crashes on a regular basis.
3. People supporting the game at Gree do not seem to care about the game either based on comments on forums.
4. Having said all that, when you play as a guild the people in the guilds are great people! Cooperative, helpfull. You can find the right guild for pretty much any player.
Mr Jumps about Kingdom Age, v3.4.2