I wanted to place four castles in a 2×2 square, but due to the increasing costs, I couldn't because a stray castle was placed elsewhere. Being able to sell castles would have been helpful, except for the restriction of not being able to sell the last castle.
The reason I wanted this 2x2 was that I discovered I could position my mouse in a way that allowed me to click on two castles simultaneously. So I wanted to test whether I could click on all four at once. However, while furiously clicking my mouse button, I slipped and accidentally clicked the Prev button. :D
