New buildings? And troops?
How about a new building but it's not a defence building. The building would be called Market.
Level 1. You can trade gold for elixer for even amounts
level 2. You can trade gold and elixer and gold for dark elixer like 100,000 gold for 1,000 or 5,000 dark elixer
level 3. You can trade dark elixer for gems. Like 1,000 de for 10 gems
Also a new defense building that every 5 seconds slams the ground and knocks back troops and does low damage
Maybe a new troop. Ghost, it just flys strait through all building and suicide bombs at defenses