Treasure Defense is a tower defense game with three types of upgradeable structures and ten different spells. While the towers fire on nearby enemies automatically once they are placed by the player, spells are directly controlled and have various support or combat abilities. Mana for spells recharges over time, while coins are rewarded for enemy kills; both may drop in large quantities from specific enemies. But one has to click to pick them up!
As one unlocks more spells with game progression, smart spell selection becomes a strategic imperative. The differences between the tower types also broaden as they are upgraded, necessitating forward thinking.
As for the enemies, well, they are rather diverse. From the heavily armored knight to the ninja that fades in and out of reality, each tests the defenses in different ways as they traverse the map to steal from the player's limited supply of gems.
Sam's Related Factoid: This game is one of my all-time favorites, so I've got my fingers crossed for a speedy release of the additional episodes promised by the developers.