The gate of the feral gods

"New Achievement! Total, Utter Failure. You failed a quest less than five minutes after you received it. Now that's talent. A floating fortress occupied by warrior gnomes. A castle made of sand. A derelict submarine guarded by malfunctioning machines. A haunted crypt surrounded by lethal traps. It was supposed to be easy. One bubble. Four castles. Fifteen days. Capture each one, and the stairwell is unlocked. Here's the thing. It's never easy. Ca...