LibertyRansom
Augur
The sequel to Kingdom Rush is out. The game is a Tower Defense/RPG game and imo, the best in the category. Very well made. Pretty addictive and very difficult. Good for losing a few hours here and there casually.
http://armorgames.com/play/15717/kingdom-rush-frontiers
http://armorgames.com/play/15717/kingdom-rush-frontiers