Swamp Defense 2, a tower defense game, has just gone Free. This game was released last week at $2.48 and went on sale 2 days ago for $0.99. If you picked it up while it was on sale, a quick chat with Amazon’s customer service should get you a refund. According to the developer, the game will be free today and tomorrow. This game is full of content with 54 unlockable maps and 9 unique tower types. The game carries a 4 out of 5 star rating on Google Play and requires a game controller to play.