Kingdom: New Lands is currently available in the
latest humble bundle.
It is a combination of tower defense, city management, and exploration. You are a king/queen, whose job is to grow your village through the day so that it can protect itself from invasions at night. This is done by collecting coins and allocating it to whatever you think is best - recruit a farmer, build a wall or try to save up for a catapult?
I've loved the experience and its pixel art.